remove lib/libsqlite3, it has moved back to ports

1 files changed, 0 insertions, 5616 deletions

diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c
deleted file mode 100644
index fad46f0b470..00000000000
--- a/lib/libsqlite3/src/select.c
+++ /dev/null
@@ -1,5616 +0,0 @@
-/*
-** 2001 September 15
-**
-** The author disclaims copyright to this source code.  In place of
-** a legal notice, here is a blessing:
-**
-**    May you do good and not evil.
-**    May you find forgiveness for yourself and forgive others.
-**    May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This file contains C code routines that are called by the parser
-** to handle SELECT statements in SQLite.
-*/
-#include "sqliteInt.h"
-
-/*
-** Trace output macros
-*/
-#if SELECTTRACE_ENABLED
-/***/ int sqlite3SelectTrace = 0;
-# define SELECTTRACE(K,P,S,X)  \
-  if(sqlite3SelectTrace&(K))   \
-    sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",\
-        (S)->zSelName,(S)),\
-    sqlite3DebugPrintf X
-#else
-# define SELECTTRACE(K,P,S,X)
-#endif
-
-
-/*
-** An instance of the following object is used to record information about
-** how to process the DISTINCT keyword, to simplify passing that information
-** into the selectInnerLoop() routine.
-*/
-typedef struct DistinctCtx DistinctCtx;
-struct DistinctCtx {
-  u8 isTnct;      /* True if the DISTINCT keyword is present */
-  u8 eTnctType;   /* One of the WHERE_DISTINCT_* operators */
-  int tabTnct;    /* Ephemeral table used for DISTINCT processing */
-  int addrTnct;   /* Address of OP_OpenEphemeral opcode for tabTnct */
-};
-
-/*
-** An instance of the following object is used to record information about
-** the ORDER BY (or GROUP BY) clause of query is being coded.
-*/
-typedef struct SortCtx SortCtx;
-struct SortCtx {
-  ExprList *pOrderBy;   /* The ORDER BY (or GROUP BY clause) */
-  int nOBSat;           /* Number of ORDER BY terms satisfied by indices */
-  int iECursor;         /* Cursor number for the sorter */
-  int regReturn;        /* Register holding block-output return address */
-  int labelBkOut;       /* Start label for the block-output subroutine */
-  int addrSortIndex;    /* Address of the OP_SorterOpen or OP_OpenEphemeral */
-  u8 sortFlags;         /* Zero or more SORTFLAG_* bits */
-};
-#define SORTFLAG_UseSorter  0x01   /* Use SorterOpen instead of OpenEphemeral */
-
-/*
-** Delete all the content of a Select structure.  Deallocate the structure
-** itself only if bFree is true.
-*/
-static void clearSelect(sqlite3 *db, Select *p, int bFree){
-  while( p ){
-    Select *pPrior = p->pPrior;
-    sqlite3ExprListDelete(db, p->pEList);
-    sqlite3SrcListDelete(db, p->pSrc);
-    sqlite3ExprDelete(db, p->pWhere);
-    sqlite3ExprListDelete(db, p->pGroupBy);
-    sqlite3ExprDelete(db, p->pHaving);
-    sqlite3ExprListDelete(db, p->pOrderBy);
-    sqlite3ExprDelete(db, p->pLimit);
-    sqlite3ExprDelete(db, p->pOffset);
-    sqlite3WithDelete(db, p->pWith);
-    if( bFree ) sqlite3DbFree(db, p);
-    p = pPrior;
-    bFree = 1;
-  }
-}
-
-/*
-** Initialize a SelectDest structure.
-*/
-void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
-  pDest->eDest = (u8)eDest;
-  pDest->iSDParm = iParm;
-  pDest->affSdst = 0;
-  pDest->iSdst = 0;
-  pDest->nSdst = 0;
-}
-
-
-/*
-** Allocate a new Select structure and return a pointer to that
-** structure.
-*/
-Select *sqlite3SelectNew(
-  Parse *pParse,        /* Parsing context */
-  ExprList *pEList,     /* which columns to include in the result */
-  SrcList *pSrc,        /* the FROM clause -- which tables to scan */
-  Expr *pWhere,         /* the WHERE clause */
-  ExprList *pGroupBy,   /* the GROUP BY clause */
-  Expr *pHaving,        /* the HAVING clause */
-  ExprList *pOrderBy,   /* the ORDER BY clause */
-  u16 selFlags,         /* Flag parameters, such as SF_Distinct */
-  Expr *pLimit,         /* LIMIT value.  NULL means not used */
-  Expr *pOffset         /* OFFSET value.  NULL means no offset */
-){
-  Select *pNew;
-  Select standin;
-  sqlite3 *db = pParse->db;
-  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
-  if( pNew==0 ){
-    assert( db->mallocFailed );
-    pNew = &standin;
-    memset(pNew, 0, sizeof(*pNew));
-  }
-  if( pEList==0 ){
-    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0));
-  }
-  pNew->pEList = pEList;
-  if( pSrc==0 ) pSrc = sqlite3DbMallocZero(db, sizeof(*pSrc));
-  pNew->pSrc = pSrc;
-  pNew->pWhere = pWhere;
-  pNew->pGroupBy = pGroupBy;
-  pNew->pHaving = pHaving;
-  pNew->pOrderBy = pOrderBy;
-  pNew->selFlags = selFlags;
-  pNew->op = TK_SELECT;
-  pNew->pLimit = pLimit;
-  pNew->pOffset = pOffset;
-  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0 || db->mallocFailed!=0 );
-  pNew->addrOpenEphm[0] = -1;
-  pNew->addrOpenEphm[1] = -1;
-  if( db->mallocFailed ) {
-    clearSelect(db, pNew, pNew!=&standin);
-    pNew = 0;
-  }else{
-    assert( pNew->pSrc!=0 || pParse->nErr>0 );
-  }
-  assert( pNew!=&standin );
-  return pNew;
-}
-
-#if SELECTTRACE_ENABLED
-/*
-** Set the name of a Select object
-*/
-void sqlite3SelectSetName(Select *p, const char *zName){
-  if( p && zName ){
-    sqlite3_snprintf(sizeof(p->zSelName), p->zSelName, "%s", zName);
-  }
-}
-#endif
-
-
-/*
-** Delete the given Select structure and all of its substructures.
-*/
-void sqlite3SelectDelete(sqlite3 *db, Select *p){
-  clearSelect(db, p, 1);
-}
-
-/*
-** Return a pointer to the right-most SELECT statement in a compound.
-*/
-static Select *findRightmost(Select *p){
-  while( p->pNext ) p = p->pNext;
-  return p;
-}
-
-/*
-** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
-** type of join.  Return an integer constant that expresses that type
-** in terms of the following bit values:
-**
-**     JT_INNER
-**     JT_CROSS
-**     JT_OUTER
-**     JT_NATURAL
-**     JT_LEFT
-**     JT_RIGHT
-**
-** A full outer join is the combination of JT_LEFT and JT_RIGHT.
-**
-** If an illegal or unsupported join type is seen, then still return
-** a join type, but put an error in the pParse structure.
-*/
-int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
-  int jointype = 0;
-  Token *apAll[3];
-  Token *p;
-                             /*   0123456789 123456789 123456789 123 */
-  static const char zKeyText[] = "naturaleftouterightfullinnercross";
-  static const struct {
-    u8 i;        /* Beginning of keyword text in zKeyText[] */
-    u8 nChar;    /* Length of the keyword in characters */
-    u8 code;     /* Join type mask */
-  } aKeyword[] = {
-    /* natural */ { 0,  7, JT_NATURAL                },
-    /* left    */ { 6,  4, JT_LEFT|JT_OUTER          },
-    /* outer   */ { 10, 5, JT_OUTER                  },
-    /* right   */ { 14, 5, JT_RIGHT|JT_OUTER         },
-    /* full    */ { 19, 4, JT_LEFT|JT_RIGHT|JT_OUTER },
-    /* inner   */ { 23, 5, JT_INNER                  },
-    /* cross   */ { 28, 5, JT_INNER|JT_CROSS         },
-  };
-  int i, j;
-  apAll[0] = pA;
-  apAll[1] = pB;
-  apAll[2] = pC;
-  for(i=0; i<3 && apAll[i]; i++){
-    p = apAll[i];
-    for(j=0; j<ArraySize(aKeyword); j++){
-      if( p->n==aKeyword[j].nChar 
-          && sqlite3StrNICmp((char*)p->z, &zKeyText[aKeyword[j].i], p->n)==0 ){
-        jointype |= aKeyword[j].code;
-        break;
-      }
-    }
-    testcase( j==0 || j==1 || j==2 || j==3 || j==4 || j==5 || j==6 );
-    if( j>=ArraySize(aKeyword) ){
-      jointype |= JT_ERROR;
-      break;
-    }
-  }
-  if(
-     (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||
-     (jointype & JT_ERROR)!=0
-  ){
-    const char *zSp = " ";
-    assert( pB!=0 );
-    if( pC==0 ){ zSp++; }
-    sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
-       "%T %T%s%T", pA, pB, zSp, pC);
-    jointype = JT_INNER;
-  }else if( (jointype & JT_OUTER)!=0 
-         && (jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ){
-    sqlite3ErrorMsg(pParse, 
-      "RIGHT and FULL OUTER JOINs are not currently supported");
-    jointype = JT_INNER;
-  }
-  return jointype;
-}
-
-/*
-** Return the index of a column in a table.  Return -1 if the column
-** is not contained in the table.
-*/
-static int columnIndex(Table *pTab, const char *zCol){
-  int i;
-  for(i=0; i<pTab->nCol; i++){
-    if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
-  }
-  return -1;
-}
-
-/*
-** Search the first N tables in pSrc, from left to right, looking for a
-** table that has a column named zCol.  
-**
-** When found, set *piTab and *piCol to the table index and column index
-** of the matching column and return TRUE.
-**
-** If not found, return FALSE.
-*/
-static int tableAndColumnIndex(
-  SrcList *pSrc,       /* Array of tables to search */
-  int N,               /* Number of tables in pSrc->a[] to search */
-  const char *zCol,    /* Name of the column we are looking for */
-  int *piTab,          /* Write index of pSrc->a[] here */
-  int *piCol           /* Write index of pSrc->a[*piTab].pTab->aCol[] here */
-){
-  int i;               /* For looping over tables in pSrc */
-  int iCol;            /* Index of column matching zCol */
-
-  assert( (piTab==0)==(piCol==0) );  /* Both or neither are NULL */
-  for(i=0; i<N; i++){
-    iCol = columnIndex(pSrc->a[i].pTab, zCol);
-    if( iCol>=0 ){
-      if( piTab ){
-        *piTab = i;
-        *piCol = iCol;
-      }
-      return 1;
-    }
-  }
-  return 0;
-}
-
-/*
-** This function is used to add terms implied by JOIN syntax to the
-** WHERE clause expression of a SELECT statement. The new term, which
-** is ANDed with the existing WHERE clause, is of the form:
-**
-**    (tab1.col1 = tab2.col2)
-**
-** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the 
-** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is
-** column iColRight of tab2.
-*/
-static void addWhereTerm(
-  Parse *pParse,                  /* Parsing context */
-  SrcList *pSrc,                  /* List of tables in FROM clause */
-  int iLeft,                      /* Index of first table to join in pSrc */
-  int iColLeft,                   /* Index of column in first table */
-  int iRight,                     /* Index of second table in pSrc */
-  int iColRight,                  /* Index of column in second table */
-  int isOuterJoin,                /* True if this is an OUTER join */
-  Expr **ppWhere                  /* IN/OUT: The WHERE clause to add to */
-){
-  sqlite3 *db = pParse->db;
-  Expr *pE1;
-  Expr *pE2;
-  Expr *pEq;
-
-  assert( iLeft<iRight );
-  assert( pSrc->nSrc>iRight );
-  assert( pSrc->a[iLeft].pTab );
-  assert( pSrc->a[iRight].pTab );
-
-  pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
-  pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);
-
-  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
-  if( pEq && isOuterJoin ){
-    ExprSetProperty(pEq, EP_FromJoin);
-    assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
-    ExprSetVVAProperty(pEq, EP_NoReduce);
-    pEq->iRightJoinTable = (i16)pE2->iTable;
-  }
-  *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq);
-}
-
-/*
-** Set the EP_FromJoin property on all terms of the given expression.
-** And set the Expr.iRightJoinTable to iTable for every term in the
-** expression.
-**
-** The EP_FromJoin property is used on terms of an expression to tell
-** the LEFT OUTER JOIN processing logic that this term is part of the
-** join restriction specified in the ON or USING clause and not a part
-** of the more general WHERE clause.  These terms are moved over to the
-** WHERE clause during join processing but we need to remember that they
-** originated in the ON or USING clause.
-**
-** The Expr.iRightJoinTable tells the WHERE clause processing that the
-** expression depends on table iRightJoinTable even if that table is not
-** explicitly mentioned in the expression.  That information is needed
-** for cases like this:
-**
-**    SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
-**
-** The where clause needs to defer the handling of the t1.x=5
-** term until after the t2 loop of the join.  In that way, a
-** NULL t2 row will be inserted whenever t1.x!=5.  If we do not
-** defer the handling of t1.x=5, it will be processed immediately
-** after the t1 loop and rows with t1.x!=5 will never appear in
-** the output, which is incorrect.
-*/
-static void setJoinExpr(Expr *p, int iTable){
-  while( p ){
-    ExprSetProperty(p, EP_FromJoin);
-    assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
-    ExprSetVVAProperty(p, EP_NoReduce);
-    p->iRightJoinTable = (i16)iTable;
-    if( p->op==TK_FUNCTION && p->x.pList ){
-      int i;
-      for(i=0; i<p->x.pList->nExpr; i++){
-        setJoinExpr(p->x.pList->a[i].pExpr, iTable);
-      }
-    }
-    setJoinExpr(p->pLeft, iTable);
-    p = p->pRight;
-  } 
-}
-
-/*
-** This routine processes the join information for a SELECT statement.
-** ON and USING clauses are converted into extra terms of the WHERE clause.
-** NATURAL joins also create extra WHERE clause terms.
-**
-** The terms of a FROM clause are contained in the Select.pSrc structure.
-** The left most table is the first entry in Select.pSrc.  The right-most
-** table is the last entry.  The join operator is held in the entry to
-** the left.  Thus entry 0 contains the join operator for the join between
-** entries 0 and 1.  Any ON or USING clauses associated with the join are
-** also attached to the left entry.
-**
-** This routine returns the number of errors encountered.
-*/
-static int sqliteProcessJoin(Parse *pParse, Select *p){
-  SrcList *pSrc;                  /* All tables in the FROM clause */
-  int i, j;                       /* Loop counters */
-  struct SrcList_item *pLeft;     /* Left table being joined */
-  struct SrcList_item *pRight;    /* Right table being joined */
-
-  pSrc = p->pSrc;
-  pLeft = &pSrc->a[0];
-  pRight = &pLeft[1];
-  for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
-    Table *pLeftTab = pLeft->pTab;
-    Table *pRightTab = pRight->pTab;
-    int isOuter;
-
-    if( NEVER(pLeftTab==0 || pRightTab==0) ) continue;
-    isOuter = (pRight->fg.jointype & JT_OUTER)!=0;
-
-    /* When the NATURAL keyword is present, add WHERE clause terms for
-    ** every column that the two tables have in common.
-    */
-    if( pRight->fg.jointype & JT_NATURAL ){
-      if( pRight->pOn || pRight->pUsing ){
-        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
-           "an ON or USING clause", 0);
-        return 1;
-      }
-      for(j=0; j<pRightTab->nCol; j++){
-        char *zName;   /* Name of column in the right table */
-        int iLeft;     /* Matching left table */
-        int iLeftCol;  /* Matching column in the left table */
-
-        zName = pRightTab->aCol[j].zName;
-        if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) ){
-          addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j,
-                       isOuter, &p->pWhere);
-        }
-      }
-    }
-
-    /* Disallow both ON and USING clauses in the same join
-    */
-    if( pRight->pOn && pRight->pUsing ){
-      sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
-        "clauses in the same join");
-      return 1;
-    }
-
-    /* Add the ON clause to the end of the WHERE clause, connected by
-    ** an AND operator.
-    */
-    if( pRight->pOn ){
-      if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor);
-      p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
-      pRight->pOn = 0;
-    }
-
-    /* Create extra terms on the WHERE clause for each column named
-    ** in the USING clause.  Example: If the two tables to be joined are 
-    ** A and B and the USING clause names X, Y, and Z, then add this
-    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
-    ** Report an error if any column mentioned in the USING clause is
-    ** not contained in both tables to be joined.
-    */
-    if( pRight->pUsing ){
-      IdList *pList = pRight->pUsing;
-      for(j=0; j<pList->nId; j++){
-        char *zName;     /* Name of the term in the USING clause */
-        int iLeft;       /* Table on the left with matching column name */
-        int iLeftCol;    /* Column number of matching column on the left */
-        int iRightCol;   /* Column number of matching column on the right */
-
-        zName = pList->a[j].zName;
-        iRightCol = columnIndex(pRightTab, zName);
-        if( iRightCol<0
-         || !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol)
-        ){
-          sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
-            "not present in both tables", zName);
-          return 1;
-        }
-        addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol,
-                     isOuter, &p->pWhere);
-      }
-    }
-  }
-  return 0;
-}
-
-/* Forward reference */
-static KeyInfo *keyInfoFromExprList(
-  Parse *pParse,       /* Parsing context */
-  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
-  int iStart,          /* Begin with this column of pList */
-  int nExtra           /* Add this many extra columns to the end */
-);
-
-/*
-** Generate code that will push the record in registers regData
-** through regData+nData-1 onto the sorter.
-*/
-static void pushOntoSorter(
-  Parse *pParse,         /* Parser context */
-  SortCtx *pSort,        /* Information about the ORDER BY clause */
-  Select *pSelect,       /* The whole SELECT statement */
-  int regData,           /* First register holding data to be sorted */
-  int regOrigData,       /* First register holding data before packing */
-  int nData,             /* Number of elements in the data array */
-  int nPrefixReg         /* No. of reg prior to regData available for use */
-){
-  Vdbe *v = pParse->pVdbe;                         /* Stmt under construction */
-  int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0);
-  int nExpr = pSort->pOrderBy->nExpr;              /* No. of ORDER BY terms */
-  int nBase = nExpr + bSeq + nData;                /* Fields in sorter record */
-  int regBase;                                     /* Regs for sorter record */
-  int regRecord = ++pParse->nMem;                  /* Assembled sorter record */
-  int nOBSat = pSort->nOBSat;                      /* ORDER BY terms to skip */
-  int op;                            /* Opcode to add sorter record to sorter */
-
-  assert( bSeq==0 || bSeq==1 );
-  assert( nData==1 || regData==regOrigData );
-  if( nPrefixReg ){
-    assert( nPrefixReg==nExpr+bSeq );
-    regBase = regData - nExpr - bSeq;
-  }else{
-    regBase = pParse->nMem + 1;
-    pParse->nMem += nBase;
-  }
-  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
-                          SQLITE_ECEL_DUP|SQLITE_ECEL_REF);
-  if( bSeq ){
-    sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
-  }
-  if( nPrefixReg==0 ){
-    sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
-  }
-
-  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
-  if( nOBSat>0 ){
-    int regPrevKey;   /* The first nOBSat columns of the previous row */
-    int addrFirst;    /* Address of the OP_IfNot opcode */
-    int addrJmp;      /* Address of the OP_Jump opcode */
-    VdbeOp *pOp;      /* Opcode that opens the sorter */
-    int nKey;         /* Number of sorting key columns, including OP_Sequence */
-    KeyInfo *pKI;     /* Original KeyInfo on the sorter table */
-
-    regPrevKey = pParse->nMem+1;
-    pParse->nMem += pSort->nOBSat;
-    nKey = nExpr - pSort->nOBSat + bSeq;
-    if( bSeq ){
-      addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); 
-    }else{
-      addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor);
-    }
-    VdbeCoverage(v);
-    sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
-    pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
-    if( pParse->db->mallocFailed ) return;
-    pOp->p2 = nKey + nData;
-    pKI = pOp->p4.pKeyInfo;
-    memset(pKI->aSortOrder, 0, pKI->nField); /* Makes OP_Jump below testable */
-    sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);
-    testcase( pKI->nXField>2 );
-    pOp->p4.pKeyInfo = keyInfoFromExprList(pParse, pSort->pOrderBy, nOBSat,
-                                           pKI->nXField-1);
-    addrJmp = sqlite3VdbeCurrentAddr(v);
-    sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
-    pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
-    pSort->regReturn = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
-    sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
-    sqlite3VdbeJumpHere(v, addrFirst);
-    sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
-    sqlite3VdbeJumpHere(v, addrJmp);
-  }
-  if( pSort->sortFlags & SORTFLAG_UseSorter ){
-    op = OP_SorterInsert;
-  }else{
-    op = OP_IdxInsert;
-  }
-  sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord);
-  if( pSelect->iLimit ){
-    int addr;
-    int iLimit;
-    if( pSelect->iOffset ){
-      iLimit = pSelect->iOffset+1;
-    }else{
-      iLimit = pSelect->iLimit;
-    }
-    addr = sqlite3VdbeAddOp3(v, OP_IfNotZero, iLimit, 0, 1); VdbeCoverage(v);
-    sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor);
-    sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor);
-    sqlite3VdbeJumpHere(v, addr);
-  }
-}
-
-/*
-** Add code to implement the OFFSET
-*/
-static void codeOffset(
-  Vdbe *v,          /* Generate code into this VM */
-  int iOffset,      /* Register holding the offset counter */
-  int iContinue     /* Jump here to skip the current record */
-){
-  if( iOffset>0 ){
-    sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);
-    VdbeComment((v, "OFFSET"));
-  }
-}
-
-/*
-** Add code that will check to make sure the N registers starting at iMem
-** form a distinct entry.  iTab is a sorting index that holds previously
-** seen combinations of the N values.  A new entry is made in iTab
-** if the current N values are new.
-**
-** A jump to addrRepeat is made and the N+1 values are popped from the
-** stack if the top N elements are not distinct.
-*/
-static void codeDistinct(
-  Parse *pParse,     /* Parsing and code generating context */
-  int iTab,          /* A sorting index used to test for distinctness */
-  int addrRepeat,    /* Jump to here if not distinct */
-  int N,             /* Number of elements */
-  int iMem           /* First element */
-){
-  Vdbe *v;
-  int r1;
-
-  v = pParse->pVdbe;
-  r1 = sqlite3GetTempReg(pParse);
-  sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
-  sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
-  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1);
-  sqlite3ReleaseTempReg(pParse, r1);
-}
-
-#ifndef SQLITE_OMIT_SUBQUERY
-/*
-** Generate an error message when a SELECT is used within a subexpression
-** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
-** column.  We do this in a subroutine because the error used to occur
-** in multiple places.  (The error only occurs in one place now, but we
-** retain the subroutine to minimize code disruption.)
-*/
-static int checkForMultiColumnSelectError(
-  Parse *pParse,       /* Parse context. */
-  SelectDest *pDest,   /* Destination of SELECT results */
-  int nExpr            /* Number of result columns returned by SELECT */
-){
-  int eDest = pDest->eDest;
-  if( nExpr>1 && (eDest==SRT_Mem || eDest==SRT_Set) ){
-    sqlite3ErrorMsg(pParse, "only a single result allowed for "
-       "a SELECT that is part of an expression");
-    return 1;
-  }else{
-    return 0;
-  }
-}
-#endif
-
-/*
-** This routine generates the code for the inside of the inner loop
-** of a SELECT.
-**
-** If srcTab is negative, then the pEList expressions
-** are evaluated in order to get the data for this row.  If srcTab is
-** zero or more, then data is pulled from srcTab and pEList is used only 
-** to get number columns and the datatype for each column.
-*/
-static void selectInnerLoop(
-  Parse *pParse,          /* The parser context */
-  Select *p,              /* The complete select statement being coded */
-  ExprList *pEList,       /* List of values being extracted */
-  int srcTab,             /* Pull data from this table */
-  SortCtx *pSort,         /* If not NULL, info on how to process ORDER BY */
-  DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */
-  SelectDest *pDest,      /* How to dispose of the results */
-  int iContinue,          /* Jump here to continue with next row */
-  int iBreak              /* Jump here to break out of the inner loop */
-){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  int hasDistinct;        /* True if the DISTINCT keyword is present */
-  int regResult;              /* Start of memory holding result set */
-  int eDest = pDest->eDest;   /* How to dispose of results */
-  int iParm = pDest->iSDParm; /* First argument to disposal method */
-  int nResultCol;             /* Number of result columns */
-  int nPrefixReg = 0;         /* Number of extra registers before regResult */
-
-  assert( v );
-  assert( pEList!=0 );
-  hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
-  if( pSort && pSort->pOrderBy==0 ) pSort = 0;
-  if( pSort==0 && !hasDistinct ){
-    assert( iContinue!=0 );
-    codeOffset(v, p->iOffset, iContinue);
-  }
-
-  /* Pull the requested columns.
-  */
-  nResultCol = pEList->nExpr;
-
-  if( pDest->iSdst==0 ){
-    if( pSort ){
-      nPrefixReg = pSort->pOrderBy->nExpr;
-      if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++;
-      pParse->nMem += nPrefixReg;
-    }
-    pDest->iSdst = pParse->nMem+1;
-    pParse->nMem += nResultCol;
-  }else if( pDest->iSdst+nResultCol > pParse->nMem ){
-    /* This is an error condition that can result, for example, when a SELECT
-    ** on the right-hand side of an INSERT contains more result columns than
-    ** there are columns in the table on the left.  The error will be caught
-    ** and reported later.  But we need to make sure enough memory is allocated
-    ** to avoid other spurious errors in the meantime. */
-    pParse->nMem += nResultCol;
-  }
-  pDest->nSdst = nResultCol;
-  regResult = pDest->iSdst;
-  if( srcTab>=0 ){
-    for(i=0; i<nResultCol; i++){
-      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
-      VdbeComment((v, "%s", pEList->a[i].zName));
-    }
-  }else if( eDest!=SRT_Exists ){
-    /* If the destination is an EXISTS(...) expression, the actual
-    ** values returned by the SELECT are not required.
-    */
-    u8 ecelFlags;
-    if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){
-      ecelFlags = SQLITE_ECEL_DUP;
-    }else{
-      ecelFlags = 0;
-    }
-    sqlite3ExprCodeExprList(pParse, pEList, regResult, 0, ecelFlags);
-  }
-
-  /* If the DISTINCT keyword was present on the SELECT statement
-  ** and this row has been seen before, then do not make this row
-  ** part of the result.
-  */
-  if( hasDistinct ){
-    switch( pDistinct->eTnctType ){
-      case WHERE_DISTINCT_ORDERED: {
-        VdbeOp *pOp;            /* No longer required OpenEphemeral instr. */
-        int iJump;              /* Jump destination */
-        int regPrev;            /* Previous row content */
-
-        /* Allocate space for the previous row */
-        regPrev = pParse->nMem+1;
-        pParse->nMem += nResultCol;
-
-        /* Change the OP_OpenEphemeral coded earlier to an OP_Null
-        ** sets the MEM_Cleared bit on the first register of the
-        ** previous value.  This will cause the OP_Ne below to always
-        ** fail on the first iteration of the loop even if the first
-        ** row is all NULLs.
-        */
-        sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
-        pOp = sqlite3VdbeGetOp(v, pDistinct->addrTnct);
-        pOp->opcode = OP_Null;
-        pOp->p1 = 1;
-        pOp->p2 = regPrev;
-
-        iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;
-        for(i=0; i<nResultCol; i++){
-          CollSeq *pColl = sqlite3ExprCollSeq(pParse, pEList->a[i].pExpr);
-          if( i<nResultCol-1 ){
-            sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);
-            VdbeCoverage(v);
-          }else{
-            sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);
-            VdbeCoverage(v);
-           }
-          sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
-          sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
-        }
-        assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed );
-        sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);
-        break;
-      }
-
-      case WHERE_DISTINCT_UNIQUE: {
-        sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
-        break;
-      }
-
-      default: {
-        assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
-        codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,
-                     regResult);
-        break;
-      }
-    }
-    if( pSort==0 ){
-      codeOffset(v, p->iOffset, iContinue);
-    }
-  }
-
-  switch( eDest ){
-    /* In this mode, write each query result to the key of the temporary
-    ** table iParm.
-    */
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-    case SRT_Union: {
-      int r1;
-      r1 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
-      sqlite3ReleaseTempReg(pParse, r1);
-      break;
-    }
-
-    /* Construct a record from the query result, but instead of
-    ** saving that record, use it as a key to delete elements from
-    ** the temporary table iParm.
-    */
-    case SRT_Except: {
-      sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);
-      break;
-    }
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
-
-    /* Store the result as data using a unique key.
-    */
-    case SRT_Fifo:
-    case SRT_DistFifo:
-    case SRT_Table:
-    case SRT_EphemTab: {
-      int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
-      testcase( eDest==SRT_Table );
-      testcase( eDest==SRT_EphemTab );
-      testcase( eDest==SRT_Fifo );
-      testcase( eDest==SRT_DistFifo );
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
-#ifndef SQLITE_OMIT_CTE
-      if( eDest==SRT_DistFifo ){
-        /* If the destination is DistFifo, then cursor (iParm+1) is open
-        ** on an ephemeral index. If the current row is already present
-        ** in the index, do not write it to the output. If not, add the
-        ** current row to the index and proceed with writing it to the
-        ** output table as well.  */
-        int addr = sqlite3VdbeCurrentAddr(v) + 4;
-        sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);
-        VdbeCoverage(v);
-        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1);
-        assert( pSort==0 );
-      }
-#endif
-      if( pSort ){
-        pushOntoSorter(pParse, pSort, p, r1+nPrefixReg,regResult,1,nPrefixReg);
-      }else{
-        int r2 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
-        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
-        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-        sqlite3ReleaseTempReg(pParse, r2);
-      }
-      sqlite3ReleaseTempRange(pParse, r1, nPrefixReg+1);
-      break;
-    }
-
-#ifndef SQLITE_OMIT_SUBQUERY
-    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
-    ** then there should be a single item on the stack.  Write this
-    ** item into the set table with bogus data.
-    */
-    case SRT_Set: {
-      assert( nResultCol==1 );
-      pDest->affSdst =
-                  sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst);
-      if( pSort ){
-        /* At first glance you would think we could optimize out the
-        ** ORDER BY in this case since the order of entries in the set
-        ** does not matter.  But there might be a LIMIT clause, in which
-        ** case the order does matter */
-        pushOntoSorter(pParse, pSort, p, regResult, regResult, 1, nPrefixReg);
-      }else{
-        int r1 = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult,1,r1, &pDest->affSdst, 1);
-        sqlite3ExprCacheAffinityChange(pParse, regResult, 1);
-        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
-        sqlite3ReleaseTempReg(pParse, r1);
-      }
-      break;
-    }
-
-    /* If any row exist in the result set, record that fact and abort.
-    */
-    case SRT_Exists: {
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-
-    /* If this is a scalar select that is part of an expression, then
-    ** store the results in the appropriate memory cell and break out
-    ** of the scan loop.
-    */
-    case SRT_Mem: {
-      assert( nResultCol==1 );
-      if( pSort ){
-        pushOntoSorter(pParse, pSort, p, regResult, regResult, 1, nPrefixReg);
-      }else{
-        assert( regResult==iParm );
-        /* The LIMIT clause will jump out of the loop for us */
-      }
-      break;
-    }
-#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
-
-    case SRT_Coroutine:       /* Send data to a co-routine */
-    case SRT_Output: {        /* Return the results */
-      testcase( eDest==SRT_Coroutine );
-      testcase( eDest==SRT_Output );
-      if( pSort ){
-        pushOntoSorter(pParse, pSort, p, regResult, regResult, nResultCol,
-                       nPrefixReg);
-      }else if( eDest==SRT_Coroutine ){
-        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
-      }else{
-        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
-        sqlite3ExprCacheAffinityChange(pParse, regResult, nResultCol);
-      }
-      break;
-    }
-
-#ifndef SQLITE_OMIT_CTE
-    /* Write the results into a priority queue that is order according to
-    ** pDest->pOrderBy (in pSO).  pDest->iSDParm (in iParm) is the cursor for an
-    ** index with pSO->nExpr+2 columns.  Build a key using pSO for the first
-    ** pSO->nExpr columns, then make sure all keys are unique by adding a
-    ** final OP_Sequence column.  The last column is the record as a blob.
-    */
-    case SRT_DistQueue:
-    case SRT_Queue: {
-      int nKey;
-      int r1, r2, r3;
-      int addrTest = 0;
-      ExprList *pSO;
-      pSO = pDest->pOrderBy;
-      assert( pSO );
-      nKey = pSO->nExpr;
-      r1 = sqlite3GetTempReg(pParse);
-      r2 = sqlite3GetTempRange(pParse, nKey+2);
-      r3 = r2+nKey+1;
-      if( eDest==SRT_DistQueue ){
-        /* If the destination is DistQueue, then cursor (iParm+1) is open
-        ** on a second ephemeral index that holds all values every previously
-        ** added to the queue. */
-        addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0, 
-                                        regResult, nResultCol);
-        VdbeCoverage(v);
-      }
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);
-      if( eDest==SRT_DistQueue ){
-        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);
-        sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
-      }
-      for(i=0; i<nKey; i++){
-        sqlite3VdbeAddOp2(v, OP_SCopy,
-                          regResult + pSO->a[i].u.x.iOrderByCol - 1,
-                          r2+i);
-      }
-      sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
-      if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);
-      sqlite3ReleaseTempReg(pParse, r1);
-      sqlite3ReleaseTempRange(pParse, r2, nKey+2);
-      break;
-    }
-#endif /* SQLITE_OMIT_CTE */
-
-
-
-#if !defined(SQLITE_OMIT_TRIGGER)
-    /* Discard the results.  This is used for SELECT statements inside
-    ** the body of a TRIGGER.  The purpose of such selects is to call
-    ** user-defined functions that have side effects.  We do not care
-    ** about the actual results of the select.
-    */
-    default: {
-      assert( eDest==SRT_Discard );
-      break;
-    }
-#endif
-  }
-
-  /* Jump to the end of the loop if the LIMIT is reached.  Except, if
-  ** there is a sorter, in which case the sorter has already limited
-  ** the output for us.
-  */
-  if( pSort==0 && p->iLimit ){
-    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
-  }
-}
-
-/*
-** Allocate a KeyInfo object sufficient for an index of N key columns and
-** X extra columns.
-*/
-KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
-  KeyInfo *p = sqlite3DbMallocZero(0, 
-                   sizeof(KeyInfo) + (N+X)*(sizeof(CollSeq*)+1));
-  if( p ){
-    p->aSortOrder = (u8*)&p->aColl[N+X];
-    p->nField = (u16)N;
-    p->nXField = (u16)X;
-    p->enc = ENC(db);
-    p->db = db;
-    p->nRef = 1;
-  }else{
-    db->mallocFailed = 1;
-  }
-  return p;
-}
-
-/*
-** Deallocate a KeyInfo object
-*/
-void sqlite3KeyInfoUnref(KeyInfo *p){
-  if( p ){
-    assert( p->nRef>0 );
-    p->nRef--;
-    if( p->nRef==0 ) sqlite3DbFree(0, p);
-  }
-}
-
-/*
-** Make a new pointer to a KeyInfo object
-*/
-KeyInfo *sqlite3KeyInfoRef(KeyInfo *p){
-  if( p ){
-    assert( p->nRef>0 );
-    p->nRef++;
-  }
-  return p;
-}
-
-#ifdef SQLITE_DEBUG
-/*
-** Return TRUE if a KeyInfo object can be change.  The KeyInfo object
-** can only be changed if this is just a single reference to the object.
-**
-** This routine is used only inside of assert() statements.
-*/
-int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; }
-#endif /* SQLITE_DEBUG */
-
-/*
-** Given an expression list, generate a KeyInfo structure that records
-** the collating sequence for each expression in that expression list.
-**
-** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
-** KeyInfo structure is appropriate for initializing a virtual index to
-** implement that clause.  If the ExprList is the result set of a SELECT
-** then the KeyInfo structure is appropriate for initializing a virtual
-** index to implement a DISTINCT test.
-**
-** Space to hold the KeyInfo structure is obtained from malloc.  The calling
-** function is responsible for seeing that this structure is eventually
-** freed.
-*/
-static KeyInfo *keyInfoFromExprList(
-  Parse *pParse,       /* Parsing context */
-  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
-  int iStart,          /* Begin with this column of pList */
-  int nExtra           /* Add this many extra columns to the end */
-){
-  int nExpr;
-  KeyInfo *pInfo;
-  struct ExprList_item *pItem;
-  sqlite3 *db = pParse->db;
-  int i;
-
-  nExpr = pList->nExpr;
-  pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
-  if( pInfo ){
-    assert( sqlite3KeyInfoIsWriteable(pInfo) );
-    for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
-      CollSeq *pColl;
-      pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      if( !pColl ) pColl = db->pDfltColl;
-      pInfo->aColl[i-iStart] = pColl;
-      pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
-    }
-  }
-  return pInfo;
-}
-
-/*
-** Name of the connection operator, used for error messages.
-*/
-static const char *selectOpName(int id){
-  char *z;
-  switch( id ){
-    case TK_ALL:       z = "UNION ALL";   break;
-    case TK_INTERSECT: z = "INTERSECT";   break;
-    case TK_EXCEPT:    z = "EXCEPT";      break;
-    default:           z = "UNION";       break;
-  }
-  return z;
-}
-
-#ifndef SQLITE_OMIT_EXPLAIN
-/*
-** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function
-** is a no-op. Otherwise, it adds a single row of output to the EQP result,
-** where the caption is of the form:
-**
-**   "USE TEMP B-TREE FOR xxx"
-**
-** where xxx is one of "DISTINCT", "ORDER BY" or "GROUP BY". Exactly which
-** is determined by the zUsage argument.
-*/
-static void explainTempTable(Parse *pParse, const char *zUsage){
-  if( pParse->explain==2 ){
-    Vdbe *v = pParse->pVdbe;
-    char *zMsg = sqlite3MPrintf(pParse->db, "USE TEMP B-TREE FOR %s", zUsage);
-    sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
-  }
-}
-
-/*
-** Assign expression b to lvalue a. A second, no-op, version of this macro
-** is provided when SQLITE_OMIT_EXPLAIN is defined. This allows the code
-** in sqlite3Select() to assign values to structure member variables that
-** only exist if SQLITE_OMIT_EXPLAIN is not defined without polluting the
-** code with #ifndef directives.
-*/
-# define explainSetInteger(a, b) a = b
-
-#else
-/* No-op versions of the explainXXX() functions and macros. */
-# define explainTempTable(y,z)
-# define explainSetInteger(y,z)
-#endif
-
-#if !defined(SQLITE_OMIT_EXPLAIN) && !defined(SQLITE_OMIT_COMPOUND_SELECT)
-/*
-** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function
-** is a no-op. Otherwise, it adds a single row of output to the EQP result,
-** where the caption is of one of the two forms:
-**
-**   "COMPOSITE SUBQUERIES iSub1 and iSub2 (op)"
-**   "COMPOSITE SUBQUERIES iSub1 and iSub2 USING TEMP B-TREE (op)"
-**
-** where iSub1 and iSub2 are the integers passed as the corresponding
-** function parameters, and op is the text representation of the parameter
-** of the same name. The parameter "op" must be one of TK_UNION, TK_EXCEPT,
-** TK_INTERSECT or TK_ALL. The first form is used if argument bUseTmp is 
-** false, or the second form if it is true.
-*/
-static void explainComposite(
-  Parse *pParse,                  /* Parse context */
-  int op,                         /* One of TK_UNION, TK_EXCEPT etc. */
-  int iSub1,                      /* Subquery id 1 */
-  int iSub2,                      /* Subquery id 2 */
-  int bUseTmp                     /* True if a temp table was used */
-){
-  assert( op==TK_UNION || op==TK_EXCEPT || op==TK_INTERSECT || op==TK_ALL );
-  if( pParse->explain==2 ){
-    Vdbe *v = pParse->pVdbe;
-    char *zMsg = sqlite3MPrintf(
-        pParse->db, "COMPOUND SUBQUERIES %d AND %d %s(%s)", iSub1, iSub2,
-        bUseTmp?"USING TEMP B-TREE ":"", selectOpName(op)
-    );
-    sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
-  }
-}
-#else
-/* No-op versions of the explainXXX() functions and macros. */
-# define explainComposite(v,w,x,y,z)
-#endif
-
-/*
-** If the inner loop was generated using a non-null pOrderBy argument,
-** then the results were placed in a sorter.  After the loop is terminated
-** we need to run the sorter and output the results.  The following
-** routine generates the code needed to do that.
-*/
-static void generateSortTail(
-  Parse *pParse,    /* Parsing context */
-  Select *p,        /* The SELECT statement */
-  SortCtx *pSort,   /* Information on the ORDER BY clause */
-  int nColumn,      /* Number of columns of data */
-  SelectDest *pDest /* Write the sorted results here */
-){
-  Vdbe *v = pParse->pVdbe;                     /* The prepared statement */
-  int addrBreak = sqlite3VdbeMakeLabel(v);     /* Jump here to exit loop */
-  int addrContinue = sqlite3VdbeMakeLabel(v);  /* Jump here for next cycle */
-  int addr;
-  int addrOnce = 0;
-  int iTab;
-  ExprList *pOrderBy = pSort->pOrderBy;
-  int eDest = pDest->eDest;
-  int iParm = pDest->iSDParm;
-  int regRow;
-  int regRowid;
-  int nKey;
-  int iSortTab;                   /* Sorter cursor to read from */
-  int nSortData;                  /* Trailing values to read from sorter */
-  int i;
-  int bSeq;                       /* True if sorter record includes seq. no. */
-#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
-  struct ExprList_item *aOutEx = p->pEList->a;
-#endif
-
-  if( pSort->labelBkOut ){
-    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
-    sqlite3VdbeGoto(v, addrBreak);
-    sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
-  }
-  iTab = pSort->iECursor;
-  if( eDest==SRT_Output || eDest==SRT_Coroutine ){
-    regRowid = 0;
-    regRow = pDest->iSdst;
-    nSortData = nColumn;
-  }else{
-    regRowid = sqlite3GetTempReg(pParse);
-    regRow = sqlite3GetTempReg(pParse);
-    nSortData = 1;
-  }
-  nKey = pOrderBy->nExpr - pSort->nOBSat;
-  if( pSort->sortFlags & SORTFLAG_UseSorter ){
-    int regSortOut = ++pParse->nMem;
-    iSortTab = pParse->nTab++;
-    if( pSort->labelBkOut ){
-      addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v);
-    }
-    sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut, nKey+1+nSortData);
-    if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
-    addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
-    VdbeCoverage(v);
-    codeOffset(v, p->iOffset, addrContinue);
-    sqlite3VdbeAddOp3(v, OP_SorterData, iTab, regSortOut, iSortTab);
-    bSeq = 0;
-  }else{
-    addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);
-    codeOffset(v, p->iOffset, addrContinue);
-    iSortTab = iTab;
-    bSeq = 1;
-  }
-  for(i=0; i<nSortData; i++){
-    sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq+i, regRow+i);
-    VdbeComment((v, "%s", aOutEx[i].zName ? aOutEx[i].zName : aOutEx[i].zSpan));
-  }
-  switch( eDest ){
-    case SRT_EphemTab: {
-      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
-      sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
-      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-      break;
-    }
-#ifndef SQLITE_OMIT_SUBQUERY
-    case SRT_Set: {
-      assert( nColumn==1 );
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid,
-                        &pDest->affSdst, 1);
-      sqlite3ExprCacheAffinityChange(pParse, regRow, 1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
-      break;
-    }
-    case SRT_Mem: {
-      assert( nColumn==1 );
-      sqlite3ExprCodeMove(pParse, regRow, iParm, 1);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-#endif
-    default: {
-      assert( eDest==SRT_Output || eDest==SRT_Coroutine ); 
-      testcase( eDest==SRT_Output );
-      testcase( eDest==SRT_Coroutine );
-      if( eDest==SRT_Output ){
-        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
-        sqlite3ExprCacheAffinityChange(pParse, pDest->iSdst, nColumn);
-      }else{
-        sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
-      }
-      break;
-    }
-  }
-  if( regRowid ){
-    sqlite3ReleaseTempReg(pParse, regRow);
-    sqlite3ReleaseTempReg(pParse, regRowid);
-  }
-  /* The bottom of the loop
-  */
-  sqlite3VdbeResolveLabel(v, addrContinue);
-  if( pSort->sortFlags & SORTFLAG_UseSorter ){
-    sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);
-  }else{
-    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);
-  }
-  if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);
-  sqlite3VdbeResolveLabel(v, addrBreak);
-}
-
-/*
-** Return a pointer to a string containing the 'declaration type' of the
-** expression pExpr. The string may be treated as static by the caller.
-**
-** Also try to estimate the size of the returned value and return that
-** result in *pEstWidth.
-**
-** The declaration type is the exact datatype definition extracted from the
-** original CREATE TABLE statement if the expression is a column. The
-** declaration type for a ROWID field is INTEGER. Exactly when an expression
-** is considered a column can be complex in the presence of subqueries. The
-** result-set expression in all of the following SELECT statements is 
-** considered a column by this function.
-**
-**   SELECT col FROM tbl;
-**   SELECT (SELECT col FROM tbl;
-**   SELECT (SELECT col FROM tbl);
-**   SELECT abc FROM (SELECT col AS abc FROM tbl);
-** 
-** The declaration type for any expression other than a column is NULL.
-**
-** This routine has either 3 or 6 parameters depending on whether or not
-** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.
-*/
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,C,D,E,F)
-#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
-# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F)
-#endif
-static const char *columnTypeImpl(
-  NameContext *pNC, 
-  Expr *pExpr,
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-  const char **pzOrigDb,
-  const char **pzOrigTab,
-  const char **pzOrigCol,
-#endif
-  u8 *pEstWidth
-){
-  char const *zType = 0;
-  int j;
-  u8 estWidth = 1;
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-  char const *zOrigDb = 0;
-  char const *zOrigTab = 0;
-  char const *zOrigCol = 0;
-#endif
-
-  if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0;
-  switch( pExpr->op ){
-    case TK_AGG_COLUMN:
-    case TK_COLUMN: {
-      /* The expression is a column. Locate the table the column is being
-      ** extracted from in NameContext.pSrcList. This table may be real
-      ** database table or a subquery.
-      */
-      Table *pTab = 0;            /* Table structure column is extracted from */
-      Select *pS = 0;             /* Select the column is extracted from */
-      int iCol = pExpr->iColumn;  /* Index of column in pTab */
-      testcase( pExpr->op==TK_AGG_COLUMN );
-      testcase( pExpr->op==TK_COLUMN );
-      while( pNC && !pTab ){
-        SrcList *pTabList = pNC->pSrcList;
-        for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
-        if( j<pTabList->nSrc ){
-          pTab = pTabList->a[j].pTab;
-          pS = pTabList->a[j].pSelect;
-        }else{
-          pNC = pNC->pNext;
-        }
-      }
-
-      if( pTab==0 ){
-        /* At one time, code such as "SELECT new.x" within a trigger would
-        ** cause this condition to run.  Since then, we have restructured how
-        ** trigger code is generated and so this condition is no longer 
-        ** possible. However, it can still be true for statements like
-        ** the following:
-        **
-        **   CREATE TABLE t1(col INTEGER);
-        **   SELECT (SELECT t1.col) FROM FROM t1;
-        **
-        ** when columnType() is called on the expression "t1.col" in the 
-        ** sub-select. In this case, set the column type to NULL, even
-        ** though it should really be "INTEGER".
-        **
-        ** This is not a problem, as the column type of "t1.col" is never
-        ** used. When columnType() is called on the expression 
-        ** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT
-        ** branch below.  */
-        break;
-      }
-
-      assert( pTab && pExpr->pTab==pTab );
-      if( pS ){
-        /* The "table" is actually a sub-select or a view in the FROM clause
-        ** of the SELECT statement. Return the declaration type and origin
-        ** data for the result-set column of the sub-select.
-        */
-        if( iCol>=0 && ALWAYS(iCol<pS->pEList->nExpr) ){
-          /* If iCol is less than zero, then the expression requests the
-          ** rowid of the sub-select or view. This expression is legal (see 
-          ** test case misc2.2.2) - it always evaluates to NULL.
-          **
-          ** The ALWAYS() is because iCol>=pS->pEList->nExpr will have been
-          ** caught already by name resolution.
-          */
-          NameContext sNC;
-          Expr *p = pS->pEList->a[iCol].pExpr;
-          sNC.pSrcList = pS->pSrc;
-          sNC.pNext = pNC;
-          sNC.pParse = pNC->pParse;
-          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 
-        }
-      }else if( pTab->pSchema ){
-        /* A real table */
-        assert( !pS );
-        if( iCol<0 ) iCol = pTab->iPKey;
-        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-        if( iCol<0 ){
-          zType = "INTEGER";
-          zOrigCol = "rowid";
-        }else{
-          zType = pTab->aCol[iCol].zType;
-          zOrigCol = pTab->aCol[iCol].zName;
-          estWidth = pTab->aCol[iCol].szEst;
-        }
-        zOrigTab = pTab->zName;
-        if( pNC->pParse ){
-          int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
-          zOrigDb = pNC->pParse->db->aDb[iDb].zName;
-        }
-#else
-        if( iCol<0 ){
-          zType = "INTEGER";
-        }else{
-          zType = pTab->aCol[iCol].zType;
-          estWidth = pTab->aCol[iCol].szEst;
-        }
-#endif
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_SUBQUERY
-    case TK_SELECT: {
-      /* The expression is a sub-select. Return the declaration type and
-      ** origin info for the single column in the result set of the SELECT
-      ** statement.
-      */
-      NameContext sNC;
-      Select *pS = pExpr->x.pSelect;
-      Expr *p = pS->pEList->a[0].pExpr;
-      assert( ExprHasProperty(pExpr, EP_xIsSelect) );
-      sNC.pSrcList = pS->pSrc;
-      sNC.pNext = pNC;
-      sNC.pParse = pNC->pParse;
-      zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, &estWidth); 
-      break;
-    }
-#endif
-  }
-
-#ifdef SQLITE_ENABLE_COLUMN_METADATA  
-  if( pzOrigDb ){
-    assert( pzOrigTab && pzOrigCol );
-    *pzOrigDb = zOrigDb;
-    *pzOrigTab = zOrigTab;
-    *pzOrigCol = zOrigCol;
-  }
-#endif
-  if( pEstWidth ) *pEstWidth = estWidth;
-  return zType;
-}
-
-/*
-** Generate code that will tell the VDBE the declaration types of columns
-** in the result set.
-*/
-static void generateColumnTypes(
-  Parse *pParse,      /* Parser context */
-  SrcList *pTabList,  /* List of tables */
-  ExprList *pEList    /* Expressions defining the result set */
-){
-#ifndef SQLITE_OMIT_DECLTYPE
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  NameContext sNC;
-  sNC.pSrcList = pTabList;
-  sNC.pParse = pParse;
-  for(i=0; i<pEList->nExpr; i++){
-    Expr *p = pEList->a[i].pExpr;
-    const char *zType;
-#ifdef SQLITE_ENABLE_COLUMN_METADATA
-    const char *zOrigDb = 0;
-    const char *zOrigTab = 0;
-    const char *zOrigCol = 0;
-    zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol, 0);
-
-    /* The vdbe must make its own copy of the column-type and other 
-    ** column specific strings, in case the schema is reset before this
-    ** virtual machine is deleted.
-    */
-    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT);
-    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);
-    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);
-#else
-    zType = columnType(&sNC, p, 0, 0, 0, 0);
-#endif
-    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
-  }
-#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
-}
-
-/*
-** Generate code that will tell the VDBE the names of columns
-** in the result set.  This information is used to provide the
-** azCol[] values in the callback.
-*/
-static void generateColumnNames(
-  Parse *pParse,      /* Parser context */
-  SrcList *pTabList,  /* List of tables */
-  ExprList *pEList    /* Expressions defining the result set */
-){
-  Vdbe *v = pParse->pVdbe;
-  int i, j;
-  sqlite3 *db = pParse->db;
-  int fullNames, shortNames;
-
-#ifndef SQLITE_OMIT_EXPLAIN
-  /* If this is an EXPLAIN, skip this step */
-  if( pParse->explain ){
-    return;
-  }
-#endif
-
-  if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return;
-  pParse->colNamesSet = 1;
-  fullNames = (db->flags & SQLITE_FullColNames)!=0;
-  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
-  sqlite3VdbeSetNumCols(v, pEList->nExpr);
-  for(i=0; i<pEList->nExpr; i++){
-    Expr *p;
-    p = pEList->a[i].pExpr;
-    if( NEVER(p==0) ) continue;
-    if( pEList->a[i].zName ){
-      char *zName = pEList->a[i].zName;
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
-    }else if( (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN) && pTabList ){
-      Table *pTab;
-      char *zCol;
-      int iCol = p->iColumn;
-      for(j=0; ALWAYS(j<pTabList->nSrc); j++){
-        if( pTabList->a[j].iCursor==p->iTable ) break;
-      }
-      assert( j<pTabList->nSrc );
-      pTab = pTabList->a[j].pTab;
-      if( iCol<0 ) iCol = pTab->iPKey;
-      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
-      if( iCol<0 ){
-        zCol = "rowid";
-      }else{
-        zCol = pTab->aCol[iCol].zName;
-      }
-      if( !shortNames && !fullNames ){
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, 
-            sqlite3DbStrDup(db, pEList->a[i].zSpan), SQLITE_DYNAMIC);
-      }else if( fullNames ){
-        char *zName = 0;
-        zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);
-      }else{
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
-      }
-    }else{
-      const char *z = pEList->a[i].zSpan;
-      z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
-    }
-  }
-  generateColumnTypes(pParse, pTabList, pEList);
-}
-
-/*
-** Given an expression list (which is really the list of expressions
-** that form the result set of a SELECT statement) compute appropriate
-** column names for a table that would hold the expression list.
-**
-** All column names will be unique.
-**
-** Only the column names are computed.  Column.zType, Column.zColl,
-** and other fields of Column are zeroed.
-**
-** Return SQLITE_OK on success.  If a memory allocation error occurs,
-** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.
-*/
-int sqlite3ColumnsFromExprList(
-  Parse *pParse,          /* Parsing context */
-  ExprList *pEList,       /* Expr list from which to derive column names */
-  i16 *pnCol,             /* Write the number of columns here */
-  Column **paCol          /* Write the new column list here */
-){
-  sqlite3 *db = pParse->db;   /* Database connection */
-  int i, j;                   /* Loop counters */
-  int cnt;                    /* Index added to make the name unique */
-  Column *aCol, *pCol;        /* For looping over result columns */
-  int nCol;                   /* Number of columns in the result set */
-  Expr *p;                    /* Expression for a single result column */
-  char *zName;                /* Column name */
-  int nName;                  /* Size of name in zName[] */
-
-  if( pEList ){
-    nCol = pEList->nExpr;
-    aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
-    testcase( aCol==0 );
-  }else{
-    nCol = 0;
-    aCol = 0;
-  }
-  *pnCol = nCol;
-  *paCol = aCol;
-
-  for(i=0, pCol=aCol; i<nCol; i++, pCol++){
-    /* Get an appropriate name for the column
-    */
-    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
-    if( (zName = pEList->a[i].zName)!=0 ){
-      /* If the column contains an "AS <name>" phrase, use <name> as the name */
-      zName = sqlite3DbStrDup(db, zName);
-    }else{
-      Expr *pColExpr = p;  /* The expression that is the result column name */
-      Table *pTab;         /* Table associated with this expression */
-      while( pColExpr->op==TK_DOT ){
-        pColExpr = pColExpr->pRight;
-        assert( pColExpr!=0 );
-      }
-      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
-        /* For columns use the column name name */
-        int iCol = pColExpr->iColumn;
-        pTab = pColExpr->pTab;
-        if( iCol<0 ) iCol = pTab->iPKey;
-        zName = sqlite3MPrintf(db, "%s",
-                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
-      }else if( pColExpr->op==TK_ID ){
-        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
-        zName = sqlite3MPrintf(db, "%s", pColExpr->u.zToken);
-      }else{
-        /* Use the original text of the column expression as its name */
-        zName = sqlite3MPrintf(db, "%s", pEList->a[i].zSpan);
-      }
-    }
-    if( db->mallocFailed ){
-      sqlite3DbFree(db, zName);
-      break;
-    }
-
-    /* Make sure the column name is unique.  If the name is not unique,
-    ** append an integer to the name so that it becomes unique.
-    */
-    nName = sqlite3Strlen30(zName);
-    for(j=cnt=0; j<i; j++){
-      if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
-        char *zNewName;
-        int k;
-        for(k=nName-1; k>1 && sqlite3Isdigit(zName[k]); k--){}
-        if( k>=0 && zName[k]==':' ) nName = k;
-        zName[nName] = 0;
-        zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt);
-        sqlite3DbFree(db, zName);
-        zName = zNewName;
-        j = -1;
-        if( zName==0 ) break;
-      }
-    }
-    pCol->zName = zName;
-  }
-  if( db->mallocFailed ){
-    for(j=0; j<i; j++){
-      sqlite3DbFree(db, aCol[j].zName);
-    }
-    sqlite3DbFree(db, aCol);
-    *paCol = 0;
-    *pnCol = 0;
-    return SQLITE_NOMEM;
-  }
-  return SQLITE_OK;
-}
-
-/*
-** Add type and collation information to a column list based on
-** a SELECT statement.
-** 
-** The column list presumably came from selectColumnNamesFromExprList().
-** The column list has only names, not types or collations.  This
-** routine goes through and adds the types and collations.
-**
-** This routine requires that all identifiers in the SELECT
-** statement be resolved.
-*/
-static void selectAddColumnTypeAndCollation(
-  Parse *pParse,        /* Parsing contexts */
-  Table *pTab,          /* Add column type information to this table */
-  Select *pSelect       /* SELECT used to determine types and collations */
-){
-  sqlite3 *db = pParse->db;
-  NameContext sNC;
-  Column *pCol;
-  CollSeq *pColl;
-  int i;
-  Expr *p;
-  struct ExprList_item *a;
-  u64 szAll = 0;
-
-  assert( pSelect!=0 );
-  assert( (pSelect->selFlags & SF_Resolved)!=0 );
-  assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );
-  if( db->mallocFailed ) return;
-  memset(&sNC, 0, sizeof(sNC));
-  sNC.pSrcList = pSelect->pSrc;
-  a = pSelect->pEList->a;
-  for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
-    p = a[i].pExpr;
-    if( pCol->zType==0 ){
-      pCol->zType = sqlite3DbStrDup(db, 
-                        columnType(&sNC, p,0,0,0, &pCol->szEst));
-    }
-    szAll += pCol->szEst;
-    pCol->affinity = sqlite3ExprAffinity(p);
-    if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB;
-    pColl = sqlite3ExprCollSeq(pParse, p);
-    if( pColl && pCol->zColl==0 ){
-      pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
-    }
-  }
-  pTab->szTabRow = sqlite3LogEst(szAll*4);
-}
-
-/*
-** Given a SELECT statement, generate a Table structure that describes
-** the result set of that SELECT.
-*/
-Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){
-  Table *pTab;
-  sqlite3 *db = pParse->db;
-  int savedFlags;
-
-  savedFlags = db->flags;
-  db->flags &= ~SQLITE_FullColNames;
-  db->flags |= SQLITE_ShortColNames;
-  sqlite3SelectPrep(pParse, pSelect, 0);
-  if( pParse->nErr ) return 0;
-  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
-  db->flags = savedFlags;
-  pTab = sqlite3DbMallocZero(db, sizeof(Table) );
-  if( pTab==0 ){
-    return 0;
-  }
-  /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside
-  ** is disabled */
-  assert( db->lookaside.bEnabled==0 );
-  pTab->nRef = 1;
-  pTab->zName = 0;
-  pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
-  sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
-  selectAddColumnTypeAndCollation(pParse, pTab, pSelect);
-  pTab->iPKey = -1;
-  if( db->mallocFailed ){
-    sqlite3DeleteTable(db, pTab);
-    return 0;
-  }
-  return pTab;
-}
-
-/*
-** Get a VDBE for the given parser context.  Create a new one if necessary.
-** If an error occurs, return NULL and leave a message in pParse.
-*/
-Vdbe *sqlite3GetVdbe(Parse *pParse){
-  Vdbe *v = pParse->pVdbe;
-  if( v==0 ){
-    v = pParse->pVdbe = sqlite3VdbeCreate(pParse);
-    if( v ) sqlite3VdbeAddOp0(v, OP_Init);
-    if( pParse->pToplevel==0
-     && OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
-    ){
-      pParse->okConstFactor = 1;
-    }
-
-  }
-  return v;
-}
-
-
-/*
-** Compute the iLimit and iOffset fields of the SELECT based on the
-** pLimit and pOffset expressions.  pLimit and pOffset hold the expressions
-** that appear in the original SQL statement after the LIMIT and OFFSET
-** keywords.  Or NULL if those keywords are omitted. iLimit and iOffset 
-** are the integer memory register numbers for counters used to compute 
-** the limit and offset.  If there is no limit and/or offset, then 
-** iLimit and iOffset are negative.
-**
-** This routine changes the values of iLimit and iOffset only if
-** a limit or offset is defined by pLimit and pOffset.  iLimit and
-** iOffset should have been preset to appropriate default values (zero)
-** prior to calling this routine.
-**
-** The iOffset register (if it exists) is initialized to the value
-** of the OFFSET.  The iLimit register is initialized to LIMIT.  Register
-** iOffset+1 is initialized to LIMIT+OFFSET.
-**
-** Only if pLimit!=0 or pOffset!=0 do the limit registers get
-** redefined.  The UNION ALL operator uses this property to force
-** the reuse of the same limit and offset registers across multiple
-** SELECT statements.
-*/
-static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
-  Vdbe *v = 0;
-  int iLimit = 0;
-  int iOffset;
-  int n;
-  if( p->iLimit ) return;
-
-  /* 
-  ** "LIMIT -1" always shows all rows.  There is some
-  ** controversy about what the correct behavior should be.
-  ** The current implementation interprets "LIMIT 0" to mean
-  ** no rows.
-  */
-  sqlite3ExprCacheClear(pParse);
-  assert( p->pOffset==0 || p->pLimit!=0 );
-  if( p->pLimit ){
-    p->iLimit = iLimit = ++pParse->nMem;
-    v = sqlite3GetVdbe(pParse);
-    assert( v!=0 );
-    if( sqlite3ExprIsInteger(p->pLimit, &n) ){
-      sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
-      VdbeComment((v, "LIMIT counter"));
-      if( n==0 ){
-        sqlite3VdbeGoto(v, iBreak);
-      }else if( n>=0 && p->nSelectRow>(u64)n ){
-        p->nSelectRow = n;
-      }
-    }else{
-      sqlite3ExprCode(pParse, p->pLimit, iLimit);
-      sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
-      VdbeComment((v, "LIMIT counter"));
-      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
-    }
-    if( p->pOffset ){
-      p->iOffset = iOffset = ++pParse->nMem;
-      pParse->nMem++;   /* Allocate an extra register for limit+offset */
-      sqlite3ExprCode(pParse, p->pOffset, iOffset);
-      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
-      VdbeComment((v, "OFFSET counter"));
-      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iOffset, iOffset, 0);
-      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);
-      VdbeComment((v, "LIMIT+OFFSET"));
-      sqlite3VdbeAddOp3(v, OP_SetIfNotPos, iLimit, iOffset+1, -1);
-    }
-  }
-}
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-/*
-** Return the appropriate collating sequence for the iCol-th column of
-** the result set for the compound-select statement "p".  Return NULL if
-** the column has no default collating sequence.
-**
-** The collating sequence for the compound select is taken from the
-** left-most term of the select that has a collating sequence.
-*/
-static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
-  CollSeq *pRet;
-  if( p->pPrior ){
-    pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
-  }else{
-    pRet = 0;
-  }
-  assert( iCol>=0 );
-  /* iCol must be less than p->pEList->nExpr.  Otherwise an error would
-  ** have been thrown during name resolution and we would not have gotten
-  ** this far */
-  if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){
-    pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
-  }
-  return pRet;
-}
-
-/*
-** The select statement passed as the second parameter is a compound SELECT
-** with an ORDER BY clause. This function allocates and returns a KeyInfo
-** structure suitable for implementing the ORDER BY.
-**
-** Space to hold the KeyInfo structure is obtained from malloc. The calling
-** function is responsible for ensuring that this structure is eventually
-** freed.
-*/
-static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){
-  ExprList *pOrderBy = p->pOrderBy;
-  int nOrderBy = p->pOrderBy->nExpr;
-  sqlite3 *db = pParse->db;
-  KeyInfo *pRet = sqlite3KeyInfoAlloc(db, nOrderBy+nExtra, 1);
-  if( pRet ){
-    int i;
-    for(i=0; i<nOrderBy; i++){
-      struct ExprList_item *pItem = &pOrderBy->a[i];
-      Expr *pTerm = pItem->pExpr;
-      CollSeq *pColl;
-
-      if( pTerm->flags & EP_Collate ){
-        pColl = sqlite3ExprCollSeq(pParse, pTerm);
-      }else{
-        pColl = multiSelectCollSeq(pParse, p, pItem->u.x.iOrderByCol-1);
-        if( pColl==0 ) pColl = db->pDfltColl;
-        pOrderBy->a[i].pExpr =
-          sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);
-      }
-      assert( sqlite3KeyInfoIsWriteable(pRet) );
-      pRet->aColl[i] = pColl;
-      pRet->aSortOrder[i] = pOrderBy->a[i].sortOrder;
-    }
-  }
-
-  return pRet;
-}
-
-#ifndef SQLITE_OMIT_CTE
-/*
-** This routine generates VDBE code to compute the content of a WITH RECURSIVE
-** query of the form:
-**
-**   <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)
-**                         \___________/             \_______________/
-**                           p->pPrior                      p
-**
-**
-** There is exactly one reference to the recursive-table in the FROM clause
-** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
-**
-** The setup-query runs once to generate an initial set of rows that go
-** into a Queue table.  Rows are extracted from the Queue table one by
-** one.  Each row extracted from Queue is output to pDest.  Then the single
-** extracted row (now in the iCurrent table) becomes the content of the
-** recursive-table for a recursive-query run.  The output of the recursive-query
-** is added back into the Queue table.  Then another row is extracted from Queue
-** and the iteration continues until the Queue table is empty.
-**
-** If the compound query operator is UNION then no duplicate rows are ever
-** inserted into the Queue table.  The iDistinct table keeps a copy of all rows
-** that have ever been inserted into Queue and causes duplicates to be
-** discarded.  If the operator is UNION ALL, then duplicates are allowed.
-** 
-** If the query has an ORDER BY, then entries in the Queue table are kept in
-** ORDER BY order and the first entry is extracted for each cycle.  Without
-** an ORDER BY, the Queue table is just a FIFO.
-**
-** If a LIMIT clause is provided, then the iteration stops after LIMIT rows
-** have been output to pDest.  A LIMIT of zero means to output no rows and a
-** negative LIMIT means to output all rows.  If there is also an OFFSET clause
-** with a positive value, then the first OFFSET outputs are discarded rather
-** than being sent to pDest.  The LIMIT count does not begin until after OFFSET
-** rows have been skipped.
-*/
-static void generateWithRecursiveQuery(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The recursive SELECT to be coded */
-  SelectDest *pDest     /* What to do with query results */
-){
-  SrcList *pSrc = p->pSrc;      /* The FROM clause of the recursive query */
-  int nCol = p->pEList->nExpr;  /* Number of columns in the recursive table */
-  Vdbe *v = pParse->pVdbe;      /* The prepared statement under construction */
-  Select *pSetup = p->pPrior;   /* The setup query */
-  int addrTop;                  /* Top of the loop */
-  int addrCont, addrBreak;      /* CONTINUE and BREAK addresses */
-  int iCurrent = 0;             /* The Current table */
-  int regCurrent;               /* Register holding Current table */
-  int iQueue;                   /* The Queue table */
-  int iDistinct = 0;            /* To ensure unique results if UNION */
-  int eDest = SRT_Fifo;         /* How to write to Queue */
-  SelectDest destQueue;         /* SelectDest targetting the Queue table */
-  int i;                        /* Loop counter */
-  int rc;                       /* Result code */
-  ExprList *pOrderBy;           /* The ORDER BY clause */
-  Expr *pLimit, *pOffset;       /* Saved LIMIT and OFFSET */
-  int regLimit, regOffset;      /* Registers used by LIMIT and OFFSET */
-
-  /* Obtain authorization to do a recursive query */
-  if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;
-
-  /* Process the LIMIT and OFFSET clauses, if they exist */
-  addrBreak = sqlite3VdbeMakeLabel(v);
-  computeLimitRegisters(pParse, p, addrBreak);
-  pLimit = p->pLimit;
-  pOffset = p->pOffset;
-  regLimit = p->iLimit;
-  regOffset = p->iOffset;
-  p->pLimit = p->pOffset = 0;
-  p->iLimit = p->iOffset = 0;
-  pOrderBy = p->pOrderBy;
-
-  /* Locate the cursor number of the Current table */
-  for(i=0; ALWAYS(i<pSrc->nSrc); i++){
-    if( pSrc->a[i].fg.isRecursive ){
-      iCurrent = pSrc->a[i].iCursor;
-      break;
-    }
-  }
-
-  /* Allocate cursors numbers for Queue and Distinct.  The cursor number for
-  ** the Distinct table must be exactly one greater than Queue in order
-  ** for the SRT_DistFifo and SRT_DistQueue destinations to work. */
-  iQueue = pParse->nTab++;
-  if( p->op==TK_UNION ){
-    eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;
-    iDistinct = pParse->nTab++;
-  }else{
-    eDest = pOrderBy ? SRT_Queue : SRT_Fifo;
-  }
-  sqlite3SelectDestInit(&destQueue, eDest, iQueue);
-
-  /* Allocate cursors for Current, Queue, and Distinct. */
-  regCurrent = ++pParse->nMem;
-  sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);
-  if( pOrderBy ){
-    KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);
-    sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,
-                      (char*)pKeyInfo, P4_KEYINFO);
-    destQueue.pOrderBy = pOrderBy;
-  }else{
-    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);
-  }
-  VdbeComment((v, "Queue table"));
-  if( iDistinct ){
-    p->addrOpenEphm[0] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iDistinct, 0);
-    p->selFlags |= SF_UsesEphemeral;
-  }
-
-  /* Detach the ORDER BY clause from the compound SELECT */
-  p->pOrderBy = 0;
-
-  /* Store the results of the setup-query in Queue. */
-  pSetup->pNext = 0;
-  rc = sqlite3Select(pParse, pSetup, &destQueue);
-  pSetup->pNext = p;
-  if( rc ) goto end_of_recursive_query;
-
-  /* Find the next row in the Queue and output that row */
-  addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak); VdbeCoverage(v);
-
-  /* Transfer the next row in Queue over to Current */
-  sqlite3VdbeAddOp1(v, OP_NullRow, iCurrent); /* To reset column cache */
-  if( pOrderBy ){
-    sqlite3VdbeAddOp3(v, OP_Column, iQueue, pOrderBy->nExpr+1, regCurrent);
-  }else{
-    sqlite3VdbeAddOp2(v, OP_RowData, iQueue, regCurrent);
-  }
-  sqlite3VdbeAddOp1(v, OP_Delete, iQueue);
-
-  /* Output the single row in Current */
-  addrCont = sqlite3VdbeMakeLabel(v);
-  codeOffset(v, regOffset, addrCont);
-  selectInnerLoop(pParse, p, p->pEList, iCurrent,
-      0, 0, pDest, addrCont, addrBreak);
-  if( regLimit ){
-    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
-    VdbeCoverage(v);
-  }
-  sqlite3VdbeResolveLabel(v, addrCont);
-
-  /* Execute the recursive SELECT taking the single row in Current as
-  ** the value for the recursive-table. Store the results in the Queue.
-  */
-  if( p->selFlags & SF_Aggregate ){
-    sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
-  }else{
-    p->pPrior = 0;
-    sqlite3Select(pParse, p, &destQueue);
-    assert( p->pPrior==0 );
-    p->pPrior = pSetup;
-  }
-
-  /* Keep running the loop until the Queue is empty */
-  sqlite3VdbeGoto(v, addrTop);
-  sqlite3VdbeResolveLabel(v, addrBreak);
-
-end_of_recursive_query:
-  sqlite3ExprListDelete(pParse->db, p->pOrderBy);
-  p->pOrderBy = pOrderBy;
-  p->pLimit = pLimit;
-  p->pOffset = pOffset;
-  return;
-}
-#endif /* SQLITE_OMIT_CTE */
-
-/* Forward references */
-static int multiSelectOrderBy(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The right-most of SELECTs to be coded */
-  SelectDest *pDest     /* What to do with query results */
-);
-
-/*
-** Handle the special case of a compound-select that originates from a
-** VALUES clause.  By handling this as a special case, we avoid deep
-** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT
-** on a VALUES clause.
-**
-** Because the Select object originates from a VALUES clause:
-**   (1) It has no LIMIT or OFFSET
-**   (2) All terms are UNION ALL
-**   (3) There is no ORDER BY clause
-*/
-static int multiSelectValues(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The right-most of SELECTs to be coded */
-  SelectDest *pDest     /* What to do with query results */
-){
-  Select *pPrior;
-  int nRow = 1;
-  int rc = 0;
-  assert( p->selFlags & SF_MultiValue );
-  do{
-    assert( p->selFlags & SF_Values );
-    assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
-    assert( p->pLimit==0 );
-    assert( p->pOffset==0 );
-    assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
-    if( p->pPrior==0 ) break;
-    assert( p->pPrior->pNext==p );
-    p = p->pPrior;
-    nRow++;
-  }while(1);
-  while( p ){
-    pPrior = p->pPrior;
-    p->pPrior = 0;
-    rc = sqlite3Select(pParse, p, pDest);
-    p->pPrior = pPrior;
-    if( rc ) break;
-    p->nSelectRow = nRow;
-    p = p->pNext;
-  }
-  return rc;
-}
-
-/*
-** This routine is called to process a compound query form from
-** two or more separate queries using UNION, UNION ALL, EXCEPT, or
-** INTERSECT
-**
-** "p" points to the right-most of the two queries.  the query on the
-** left is p->pPrior.  The left query could also be a compound query
-** in which case this routine will be called recursively. 
-**
-** The results of the total query are to be written into a destination
-** of type eDest with parameter iParm.
-**
-** Example 1:  Consider a three-way compound SQL statement.
-**
-**     SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
-**
-** This statement is parsed up as follows:
-**
-**     SELECT c FROM t3
-**      |
-**      `----->  SELECT b FROM t2
-**                |
-**                `------>  SELECT a FROM t1
-**
-** The arrows in the diagram above represent the Select.pPrior pointer.
-** So if this routine is called with p equal to the t3 query, then
-** pPrior will be the t2 query.  p->op will be TK_UNION in this case.
-**
-** Notice that because of the way SQLite parses compound SELECTs, the
-** individual selects always group from left to right.
-*/
-static int multiSelect(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The right-most of SELECTs to be coded */
-  SelectDest *pDest     /* What to do with query results */
-){
-  int rc = SQLITE_OK;   /* Success code from a subroutine */
-  Select *pPrior;       /* Another SELECT immediately to our left */
-  Vdbe *v;              /* Generate code to this VDBE */
-  SelectDest dest;      /* Alternative data destination */
-  Select *pDelete = 0;  /* Chain of simple selects to delete */
-  sqlite3 *db;          /* Database connection */
-#ifndef SQLITE_OMIT_EXPLAIN
-  int iSub1 = 0;        /* EQP id of left-hand query */
-  int iSub2 = 0;        /* EQP id of right-hand query */
-#endif
-
-  /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
-  ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
-  */
-  assert( p && p->pPrior );  /* Calling function guarantees this much */
-  assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );
-  db = pParse->db;
-  pPrior = p->pPrior;
-  dest = *pDest;
-  if( pPrior->pOrderBy ){
-    sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
-      selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
-  if( pPrior->pLimit ){
-    sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
-      selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
-
-  v = sqlite3GetVdbe(pParse);
-  assert( v!=0 );  /* The VDBE already created by calling function */
-
-  /* Create the destination temporary table if necessary
-  */
-  if( dest.eDest==SRT_EphemTab ){
-    assert( p->pEList );
-    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);
-    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
-    dest.eDest = SRT_Table;
-  }
-
-  /* Special handling for a compound-select that originates as a VALUES clause.
-  */
-  if( p->selFlags & SF_MultiValue ){
-    rc = multiSelectValues(pParse, p, &dest);
-    goto multi_select_end;
-  }
-
-  /* Make sure all SELECTs in the statement have the same number of elements
-  ** in their result sets.
-  */
-  assert( p->pEList && pPrior->pEList );
-  assert( p->pEList->nExpr==pPrior->pEList->nExpr );
-
-#ifndef SQLITE_OMIT_CTE
-  if( p->selFlags & SF_Recursive ){
-    generateWithRecursiveQuery(pParse, p, &dest);
-  }else
-#endif
-
-  /* Compound SELECTs that have an ORDER BY clause are handled separately.
-  */
-  if( p->pOrderBy ){
-    return multiSelectOrderBy(pParse, p, pDest);
-  }else
-
-  /* Generate code for the left and right SELECT statements.
-  */
-  switch( p->op ){
-    case TK_ALL: {
-      int addr = 0;
-      int nLimit;
-      assert( !pPrior->pLimit );
-      pPrior->iLimit = p->iLimit;
-      pPrior->iOffset = p->iOffset;
-      pPrior->pLimit = p->pLimit;
-      pPrior->pOffset = p->pOffset;
-      explainSetInteger(iSub1, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, pPrior, &dest);
-      p->pLimit = 0;
-      p->pOffset = 0;
-      if( rc ){
-        goto multi_select_end;
-      }
-      p->pPrior = 0;
-      p->iLimit = pPrior->iLimit;
-      p->iOffset = pPrior->iOffset;
-      if( p->iLimit ){
-        addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
-        VdbeComment((v, "Jump ahead if LIMIT reached"));
-        if( p->iOffset ){
-          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iOffset, p->iOffset, 0);
-          sqlite3VdbeAddOp3(v, OP_Add, p->iLimit, p->iOffset, p->iOffset+1);
-          sqlite3VdbeAddOp3(v, OP_SetIfNotPos, p->iLimit, p->iOffset+1, -1);
-        }
-      }
-      explainSetInteger(iSub2, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, p, &dest);
-      testcase( rc!=SQLITE_OK );
-      pDelete = p->pPrior;
-      p->pPrior = pPrior;
-      p->nSelectRow += pPrior->nSelectRow;
-      if( pPrior->pLimit
-       && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
-       && nLimit>0 && p->nSelectRow > (u64)nLimit 
-      ){
-        p->nSelectRow = nLimit;
-      }
-      if( addr ){
-        sqlite3VdbeJumpHere(v, addr);
-      }
-      break;
-    }
-    case TK_EXCEPT:
-    case TK_UNION: {
-      int unionTab;    /* Cursor number of the temporary table holding result */
-      u8 op = 0;       /* One of the SRT_ operations to apply to self */
-      int priorOp;     /* The SRT_ operation to apply to prior selects */
-      Expr *pLimit, *pOffset; /* Saved values of p->nLimit and p->nOffset */
-      int addr;
-      SelectDest uniondest;
-
-      testcase( p->op==TK_EXCEPT );
-      testcase( p->op==TK_UNION );
-      priorOp = SRT_Union;
-      if( dest.eDest==priorOp ){
-        /* We can reuse a temporary table generated by a SELECT to our
-        ** right.
-        */
-        assert( p->pLimit==0 );      /* Not allowed on leftward elements */
-        assert( p->pOffset==0 );     /* Not allowed on leftward elements */
-        unionTab = dest.iSDParm;
-      }else{
-        /* We will need to create our own temporary table to hold the
-        ** intermediate results.
-        */
-        unionTab = pParse->nTab++;
-        assert( p->pOrderBy==0 );
-        addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
-        assert( p->addrOpenEphm[0] == -1 );
-        p->addrOpenEphm[0] = addr;
-        findRightmost(p)->selFlags |= SF_UsesEphemeral;
-        assert( p->pEList );
-      }
-
-      /* Code the SELECT statements to our left
-      */
-      assert( !pPrior->pOrderBy );
-      sqlite3SelectDestInit(&uniondest, priorOp, unionTab);
-      explainSetInteger(iSub1, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, pPrior, &uniondest);
-      if( rc ){
-        goto multi_select_end;
-      }
-
-      /* Code the current SELECT statement
-      */
-      if( p->op==TK_EXCEPT ){
-        op = SRT_Except;
-      }else{
-        assert( p->op==TK_UNION );
-        op = SRT_Union;
-      }
-      p->pPrior = 0;
-      pLimit = p->pLimit;
-      p->pLimit = 0;
-      pOffset = p->pOffset;
-      p->pOffset = 0;
-      uniondest.eDest = op;
-      explainSetInteger(iSub2, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, p, &uniondest);
-      testcase( rc!=SQLITE_OK );
-      /* Query flattening in sqlite3Select() might refill p->pOrderBy.
-      ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
-      sqlite3ExprListDelete(db, p->pOrderBy);
-      pDelete = p->pPrior;
-      p->pPrior = pPrior;
-      p->pOrderBy = 0;
-      if( p->op==TK_UNION ) p->nSelectRow += pPrior->nSelectRow;
-      sqlite3ExprDelete(db, p->pLimit);
-      p->pLimit = pLimit;
-      p->pOffset = pOffset;
-      p->iLimit = 0;
-      p->iOffset = 0;
-
-      /* Convert the data in the temporary table into whatever form
-      ** it is that we currently need.
-      */
-      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
-      if( dest.eDest!=priorOp ){
-        int iCont, iBreak, iStart;
-        assert( p->pEList );
-        if( dest.eDest==SRT_Output ){
-          Select *pFirst = p;
-          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-          generateColumnNames(pParse, 0, pFirst->pEList);
-        }
-        iBreak = sqlite3VdbeMakeLabel(v);
-        iCont = sqlite3VdbeMakeLabel(v);
-        computeLimitRegisters(pParse, p, iBreak);
-        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
-        iStart = sqlite3VdbeCurrentAddr(v);
-        selectInnerLoop(pParse, p, p->pEList, unionTab,
-                        0, 0, &dest, iCont, iBreak);
-        sqlite3VdbeResolveLabel(v, iCont);
-        sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); VdbeCoverage(v);
-        sqlite3VdbeResolveLabel(v, iBreak);
-        sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
-      }
-      break;
-    }
-    default: assert( p->op==TK_INTERSECT ); {
-      int tab1, tab2;
-      int iCont, iBreak, iStart;
-      Expr *pLimit, *pOffset;
-      int addr;
-      SelectDest intersectdest;
-      int r1;
-
-      /* INTERSECT is different from the others since it requires
-      ** two temporary tables.  Hence it has its own case.  Begin
-      ** by allocating the tables we will need.
-      */
-      tab1 = pParse->nTab++;
-      tab2 = pParse->nTab++;
-      assert( p->pOrderBy==0 );
-
-      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
-      assert( p->addrOpenEphm[0] == -1 );
-      p->addrOpenEphm[0] = addr;
-      findRightmost(p)->selFlags |= SF_UsesEphemeral;
-      assert( p->pEList );
-
-      /* Code the SELECTs to our left into temporary table "tab1".
-      */
-      sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);
-      explainSetInteger(iSub1, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, pPrior, &intersectdest);
-      if( rc ){
-        goto multi_select_end;
-      }
-
-      /* Code the current SELECT into temporary table "tab2"
-      */
-      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
-      assert( p->addrOpenEphm[1] == -1 );
-      p->addrOpenEphm[1] = addr;
-      p->pPrior = 0;
-      pLimit = p->pLimit;
-      p->pLimit = 0;
-      pOffset = p->pOffset;
-      p->pOffset = 0;
-      intersectdest.iSDParm = tab2;
-      explainSetInteger(iSub2, pParse->iNextSelectId);
-      rc = sqlite3Select(pParse, p, &intersectdest);
-      testcase( rc!=SQLITE_OK );
-      pDelete = p->pPrior;
-      p->pPrior = pPrior;
-      if( p->nSelectRow>pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
-      sqlite3ExprDelete(db, p->pLimit);
-      p->pLimit = pLimit;
-      p->pOffset = pOffset;
-
-      /* Generate code to take the intersection of the two temporary
-      ** tables.
-      */
-      assert( p->pEList );
-      if( dest.eDest==SRT_Output ){
-        Select *pFirst = p;
-        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-        generateColumnNames(pParse, 0, pFirst->pEList);
-      }
-      iBreak = sqlite3VdbeMakeLabel(v);
-      iCont = sqlite3VdbeMakeLabel(v);
-      computeLimitRegisters(pParse, p, iBreak);
-      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
-      r1 = sqlite3GetTempReg(pParse);
-      iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1);
-      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);
-      sqlite3ReleaseTempReg(pParse, r1);
-      selectInnerLoop(pParse, p, p->pEList, tab1,
-                      0, 0, &dest, iCont, iBreak);
-      sqlite3VdbeResolveLabel(v, iCont);
-      sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);
-      sqlite3VdbeResolveLabel(v, iBreak);
-      sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
-      sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
-      break;
-    }
-  }
-
-  explainComposite(pParse, p->op, iSub1, iSub2, p->op!=TK_ALL);
-
-  /* Compute collating sequences used by 
-  ** temporary tables needed to implement the compound select.
-  ** Attach the KeyInfo structure to all temporary tables.
-  **
-  ** This section is run by the right-most SELECT statement only.
-  ** SELECT statements to the left always skip this part.  The right-most
-  ** SELECT might also skip this part if it has no ORDER BY clause and
-  ** no temp tables are required.
-  */
-  if( p->selFlags & SF_UsesEphemeral ){
-    int i;                        /* Loop counter */
-    KeyInfo *pKeyInfo;            /* Collating sequence for the result set */
-    Select *pLoop;                /* For looping through SELECT statements */
-    CollSeq **apColl;             /* For looping through pKeyInfo->aColl[] */
-    int nCol;                     /* Number of columns in result set */
-
-    assert( p->pNext==0 );
-    nCol = p->pEList->nExpr;
-    pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
-    if( !pKeyInfo ){
-      rc = SQLITE_NOMEM;
-      goto multi_select_end;
-    }
-    for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
-      *apColl = multiSelectCollSeq(pParse, p, i);
-      if( 0==*apColl ){
-        *apColl = db->pDfltColl;
-      }
-    }
-
-    for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
-      for(i=0; i<2; i++){
-        int addr = pLoop->addrOpenEphm[i];
-        if( addr<0 ){
-          /* If [0] is unused then [1] is also unused.  So we can
-          ** always safely abort as soon as the first unused slot is found */
-          assert( pLoop->addrOpenEphm[1]<0 );
-          break;
-        }
-        sqlite3VdbeChangeP2(v, addr, nCol);
-        sqlite3VdbeChangeP4(v, addr, (char*)sqlite3KeyInfoRef(pKeyInfo),
-                            P4_KEYINFO);
-        pLoop->addrOpenEphm[i] = -1;
-      }
-    }
-    sqlite3KeyInfoUnref(pKeyInfo);
-  }
-
-multi_select_end:
-  pDest->iSdst = dest.iSdst;
-  pDest->nSdst = dest.nSdst;
-  sqlite3SelectDelete(db, pDelete);
-  return rc;
-}
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
-
-/*
-** Error message for when two or more terms of a compound select have different
-** size result sets.
-*/
-void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){
-  if( p->selFlags & SF_Values ){
-    sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
-  }else{
-    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
-      " do not have the same number of result columns", selectOpName(p->op));
-  }
-}
-
-/*
-** Code an output subroutine for a coroutine implementation of a
-** SELECT statment.
-**
-** The data to be output is contained in pIn->iSdst.  There are
-** pIn->nSdst columns to be output.  pDest is where the output should
-** be sent.
-**
-** regReturn is the number of the register holding the subroutine
-** return address.
-**
-** If regPrev>0 then it is the first register in a vector that
-** records the previous output.  mem[regPrev] is a flag that is false
-** if there has been no previous output.  If regPrev>0 then code is
-** generated to suppress duplicates.  pKeyInfo is used for comparing
-** keys.
-**
-** If the LIMIT found in p->iLimit is reached, jump immediately to
-** iBreak.
-*/
-static int generateOutputSubroutine(
-  Parse *pParse,          /* Parsing context */
-  Select *p,              /* The SELECT statement */
-  SelectDest *pIn,        /* Coroutine supplying data */
-  SelectDest *pDest,      /* Where to send the data */
-  int regReturn,          /* The return address register */
-  int regPrev,            /* Previous result register.  No uniqueness if 0 */
-  KeyInfo *pKeyInfo,      /* For comparing with previous entry */
-  int iBreak              /* Jump here if we hit the LIMIT */
-){
-  Vdbe *v = pParse->pVdbe;
-  int iContinue;
-  int addr;
-
-  addr = sqlite3VdbeCurrentAddr(v);
-  iContinue = sqlite3VdbeMakeLabel(v);
-
-  /* Suppress duplicates for UNION, EXCEPT, and INTERSECT 
-  */
-  if( regPrev ){
-    int addr1, addr2;
-    addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
-    addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
-                              (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
-    sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);
-    sqlite3VdbeJumpHere(v, addr1);
-    sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);
-    sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
-  }
-  if( pParse->db->mallocFailed ) return 0;
-
-  /* Suppress the first OFFSET entries if there is an OFFSET clause
-  */
-  codeOffset(v, p->iOffset, iContinue);
-
-  assert( pDest->eDest!=SRT_Exists );
-  assert( pDest->eDest!=SRT_Table );
-  switch( pDest->eDest ){
-    /* Store the result as data using a unique key.
-    */
-    case SRT_EphemTab: {
-      int r1 = sqlite3GetTempReg(pParse);
-      int r2 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);
-      sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);
-      sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);
-      sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
-      sqlite3ReleaseTempReg(pParse, r2);
-      sqlite3ReleaseTempReg(pParse, r1);
-      break;
-    }
-
-#ifndef SQLITE_OMIT_SUBQUERY
-    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
-    ** then there should be a single item on the stack.  Write this
-    ** item into the set table with bogus data.
-    */
-    case SRT_Set: {
-      int r1;
-      assert( pIn->nSdst==1 || pParse->nErr>0 );
-      pDest->affSdst = 
-         sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affSdst);
-      r1 = sqlite3GetTempReg(pParse);
-      sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, 1, r1, &pDest->affSdst,1);
-      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, 1);
-      sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iSDParm, r1);
-      sqlite3ReleaseTempReg(pParse, r1);
-      break;
-    }
-
-    /* If this is a scalar select that is part of an expression, then
-    ** store the results in the appropriate memory cell and break out
-    ** of the scan loop.
-    */
-    case SRT_Mem: {
-      assert( pIn->nSdst==1 || pParse->nErr>0 );  testcase( pIn->nSdst!=1 );
-      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1);
-      /* The LIMIT clause will jump out of the loop for us */
-      break;
-    }
-#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
-
-    /* The results are stored in a sequence of registers
-    ** starting at pDest->iSdst.  Then the co-routine yields.
-    */
-    case SRT_Coroutine: {
-      if( pDest->iSdst==0 ){
-        pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);
-        pDest->nSdst = pIn->nSdst;
-      }
-      sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);
-      sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
-      break;
-    }
-
-    /* If none of the above, then the result destination must be
-    ** SRT_Output.  This routine is never called with any other
-    ** destination other than the ones handled above or SRT_Output.
-    **
-    ** For SRT_Output, results are stored in a sequence of registers.  
-    ** Then the OP_ResultRow opcode is used to cause sqlite3_step() to
-    ** return the next row of result.
-    */
-    default: {
-      assert( pDest->eDest==SRT_Output );
-      sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iSdst, pIn->nSdst);
-      sqlite3ExprCacheAffinityChange(pParse, pIn->iSdst, pIn->nSdst);
-      break;
-    }
-  }
-
-  /* Jump to the end of the loop if the LIMIT is reached.
-  */
-  if( p->iLimit ){
-    sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
-  }
-
-  /* Generate the subroutine return
-  */
-  sqlite3VdbeResolveLabel(v, iContinue);
-  sqlite3VdbeAddOp1(v, OP_Return, regReturn);
-
-  return addr;
-}
-
-/*
-** Alternative compound select code generator for cases when there
-** is an ORDER BY clause.
-**
-** We assume a query of the following form:
-**
-**      <selectA>  <operator>  <selectB>  ORDER BY <orderbylist>
-**
-** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT.  The idea
-** is to code both <selectA> and <selectB> with the ORDER BY clause as
-** co-routines.  Then run the co-routines in parallel and merge the results
-** into the output.  In addition to the two coroutines (called selectA and
-** selectB) there are 7 subroutines:
-**
-**    outA:    Move the output of the selectA coroutine into the output
-**             of the compound query.
-**
-**    outB:    Move the output of the selectB coroutine into the output
-**             of the compound query.  (Only generated for UNION and
-**             UNION ALL.  EXCEPT and INSERTSECT never output a row that
-**             appears only in B.)
-**
-**    AltB:    Called when there is data from both coroutines and A<B.
-**
-**    AeqB:    Called when there is data from both coroutines and A==B.
-**
-**    AgtB:    Called when there is data from both coroutines and A>B.
-**
-**    EofA:    Called when data is exhausted from selectA.
-**
-**    EofB:    Called when data is exhausted from selectB.
-**
-** The implementation of the latter five subroutines depend on which 
-** <operator> is used:
-**
-**
-**             UNION ALL         UNION            EXCEPT          INTERSECT
-**          -------------  -----------------  --------------  -----------------
-**   AltB:   outA, nextA      outA, nextA       outA, nextA         nextA
-**
-**   AeqB:   outA, nextA         nextA             nextA         outA, nextA
-**
-**   AgtB:   outB, nextB      outB, nextB          nextB            nextB
-**
-**   EofA:   outB, nextB      outB, nextB          halt             halt
-**
-**   EofB:   outA, nextA      outA, nextA       outA, nextA         halt
-**
-** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA
-** causes an immediate jump to EofA and an EOF on B following nextB causes
-** an immediate jump to EofB.  Within EofA and EofB, and EOF on entry or
-** following nextX causes a jump to the end of the select processing.
-**
-** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled
-** within the output subroutine.  The regPrev register set holds the previously
-** output value.  A comparison is made against this value and the output
-** is skipped if the next results would be the same as the previous.
-**
-** The implementation plan is to implement the two coroutines and seven
-** subroutines first, then put the control logic at the bottom.  Like this:
-**
-**          goto Init
-**     coA: coroutine for left query (A)
-**     coB: coroutine for right query (B)
-**    outA: output one row of A
-**    outB: output one row of B (UNION and UNION ALL only)
-**    EofA: ...
-**    EofB: ...
-**    AltB: ...
-**    AeqB: ...
-**    AgtB: ...
-**    Init: initialize coroutine registers
-**          yield coA
-**          if eof(A) goto EofA
-**          yield coB
-**          if eof(B) goto EofB
-**    Cmpr: Compare A, B
-**          Jump AltB, AeqB, AgtB
-**     End: ...
-**
-** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not
-** actually called using Gosub and they do not Return.  EofA and EofB loop
-** until all data is exhausted then jump to the "end" labe.  AltB, AeqB,
-** and AgtB jump to either L2 or to one of EofA or EofB.
-*/
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-static int multiSelectOrderBy(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The right-most of SELECTs to be coded */
-  SelectDest *pDest     /* What to do with query results */
-){
-  int i, j;             /* Loop counters */
-  Select *pPrior;       /* Another SELECT immediately to our left */
-  Vdbe *v;              /* Generate code to this VDBE */
-  SelectDest destA;     /* Destination for coroutine A */
-  SelectDest destB;     /* Destination for coroutine B */
-  int regAddrA;         /* Address register for select-A coroutine */
-  int regAddrB;         /* Address register for select-B coroutine */
-  int addrSelectA;      /* Address of the select-A coroutine */
-  int addrSelectB;      /* Address of the select-B coroutine */
-  int regOutA;          /* Address register for the output-A subroutine */
-  int regOutB;          /* Address register for the output-B subroutine */
-  int addrOutA;         /* Address of the output-A subroutine */
-  int addrOutB = 0;     /* Address of the output-B subroutine */
-  int addrEofA;         /* Address of the select-A-exhausted subroutine */
-  int addrEofA_noB;     /* Alternate addrEofA if B is uninitialized */
-  int addrEofB;         /* Address of the select-B-exhausted subroutine */
-  int addrAltB;         /* Address of the A<B subroutine */
-  int addrAeqB;         /* Address of the A==B subroutine */
-  int addrAgtB;         /* Address of the A>B subroutine */
-  int regLimitA;        /* Limit register for select-A */
-  int regLimitB;        /* Limit register for select-A */
-  int regPrev;          /* A range of registers to hold previous output */
-  int savedLimit;       /* Saved value of p->iLimit */
-  int savedOffset;      /* Saved value of p->iOffset */
-  int labelCmpr;        /* Label for the start of the merge algorithm */
-  int labelEnd;         /* Label for the end of the overall SELECT stmt */
-  int addr1;            /* Jump instructions that get retargetted */
-  int op;               /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
-  KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */
-  KeyInfo *pKeyMerge;   /* Comparison information for merging rows */
-  sqlite3 *db;          /* Database connection */
-  ExprList *pOrderBy;   /* The ORDER BY clause */
-  int nOrderBy;         /* Number of terms in the ORDER BY clause */
-  int *aPermute;        /* Mapping from ORDER BY terms to result set columns */
-#ifndef SQLITE_OMIT_EXPLAIN
-  int iSub1;            /* EQP id of left-hand query */
-  int iSub2;            /* EQP id of right-hand query */
-#endif
-
-  assert( p->pOrderBy!=0 );
-  assert( pKeyDup==0 ); /* "Managed" code needs this.  Ticket #3382. */
-  db = pParse->db;
-  v = pParse->pVdbe;
-  assert( v!=0 );       /* Already thrown the error if VDBE alloc failed */
-  labelEnd = sqlite3VdbeMakeLabel(v);
-  labelCmpr = sqlite3VdbeMakeLabel(v);
-
-
-  /* Patch up the ORDER BY clause
-  */
-  op = p->op;  
-  pPrior = p->pPrior;
-  assert( pPrior->pOrderBy==0 );
-  pOrderBy = p->pOrderBy;
-  assert( pOrderBy );
-  nOrderBy = pOrderBy->nExpr;
-
-  /* For operators other than UNION ALL we have to make sure that
-  ** the ORDER BY clause covers every term of the result set.  Add
-  ** terms to the ORDER BY clause as necessary.
-  */
-  if( op!=TK_ALL ){
-    for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){
-      struct ExprList_item *pItem;
-      for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){
-        assert( pItem->u.x.iOrderByCol>0 );
-        if( pItem->u.x.iOrderByCol==i ) break;
-      }
-      if( j==nOrderBy ){
-        Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
-        if( pNew==0 ) return SQLITE_NOMEM;
-        pNew->flags |= EP_IntValue;
-        pNew->u.iValue = i;
-        pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
-        if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;
-      }
-    }
-  }
-
-  /* Compute the comparison permutation and keyinfo that is used with
-  ** the permutation used to determine if the next
-  ** row of results comes from selectA or selectB.  Also add explicit
-  ** collations to the ORDER BY clause terms so that when the subqueries
-  ** to the right and the left are evaluated, they use the correct
-  ** collation.
-  */
-  aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy);
-  if( aPermute ){
-    struct ExprList_item *pItem;
-    for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){
-      assert( pItem->u.x.iOrderByCol>0 );
-      assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
-      aPermute[i] = pItem->u.x.iOrderByCol - 1;
-    }
-    pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
-  }else{
-    pKeyMerge = 0;
-  }
-
-  /* Reattach the ORDER BY clause to the query.
-  */
-  p->pOrderBy = pOrderBy;
-  pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy, 0);
-
-  /* Allocate a range of temporary registers and the KeyInfo needed
-  ** for the logic that removes duplicate result rows when the
-  ** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL).
-  */
-  if( op==TK_ALL ){
-    regPrev = 0;
-  }else{
-    int nExpr = p->pEList->nExpr;
-    assert( nOrderBy>=nExpr || db->mallocFailed );
-    regPrev = pParse->nMem+1;
-    pParse->nMem += nExpr+1;
-    sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
-    pKeyDup = sqlite3KeyInfoAlloc(db, nExpr, 1);
-    if( pKeyDup ){
-      assert( sqlite3KeyInfoIsWriteable(pKeyDup) );
-      for(i=0; i<nExpr; i++){
-        pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
-        pKeyDup->aSortOrder[i] = 0;
-      }
-    }
-  }
- 
-  /* Separate the left and the right query from one another
-  */
-  p->pPrior = 0;
-  pPrior->pNext = 0;
-  sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");
-  if( pPrior->pPrior==0 ){
-    sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");
-  }
-
-  /* Compute the limit registers */
-  computeLimitRegisters(pParse, p, labelEnd);
-  if( p->iLimit && op==TK_ALL ){
-    regLimitA = ++pParse->nMem;
-    regLimitB = ++pParse->nMem;
-    sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit,
-                                  regLimitA);
-    sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
-  }else{
-    regLimitA = regLimitB = 0;
-  }
-  sqlite3ExprDelete(db, p->pLimit);
-  p->pLimit = 0;
-  sqlite3ExprDelete(db, p->pOffset);
-  p->pOffset = 0;
-
-  regAddrA = ++pParse->nMem;
-  regAddrB = ++pParse->nMem;
-  regOutA = ++pParse->nMem;
-  regOutB = ++pParse->nMem;
-  sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
-  sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
-
-  /* Generate a coroutine to evaluate the SELECT statement to the
-  ** left of the compound operator - the "A" select.
-  */
-  addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
-  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
-  VdbeComment((v, "left SELECT"));
-  pPrior->iLimit = regLimitA;
-  explainSetInteger(iSub1, pParse->iNextSelectId);
-  sqlite3Select(pParse, pPrior, &destA);
-  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrA);
-  sqlite3VdbeJumpHere(v, addr1);
-
-  /* Generate a coroutine to evaluate the SELECT statement on 
-  ** the right - the "B" select
-  */
-  addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
-  addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
-  VdbeComment((v, "right SELECT"));
-  savedLimit = p->iLimit;
-  savedOffset = p->iOffset;
-  p->iLimit = regLimitB;
-  p->iOffset = 0;  
-  explainSetInteger(iSub2, pParse->iNextSelectId);
-  sqlite3Select(pParse, p, &destB);
-  p->iLimit = savedLimit;
-  p->iOffset = savedOffset;
-  sqlite3VdbeAddOp1(v, OP_EndCoroutine, regAddrB);
-
-  /* Generate a subroutine that outputs the current row of the A
-  ** select as the next output row of the compound select.
-  */
-  VdbeNoopComment((v, "Output routine for A"));
-  addrOutA = generateOutputSubroutine(pParse,
-                 p, &destA, pDest, regOutA,
-                 regPrev, pKeyDup, labelEnd);
-  
-  /* Generate a subroutine that outputs the current row of the B
-  ** select as the next output row of the compound select.
-  */
-  if( op==TK_ALL || op==TK_UNION ){
-    VdbeNoopComment((v, "Output routine for B"));
-    addrOutB = generateOutputSubroutine(pParse,
-                 p, &destB, pDest, regOutB,
-                 regPrev, pKeyDup, labelEnd);
-  }
-  sqlite3KeyInfoUnref(pKeyDup);
-
-  /* Generate a subroutine to run when the results from select A
-  ** are exhausted and only data in select B remains.
-  */
-  if( op==TK_EXCEPT || op==TK_INTERSECT ){
-    addrEofA_noB = addrEofA = labelEnd;
-  }else{  
-    VdbeNoopComment((v, "eof-A subroutine"));
-    addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
-    addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);
-                                     VdbeCoverage(v);
-    sqlite3VdbeGoto(v, addrEofA);
-    p->nSelectRow += pPrior->nSelectRow;
-  }
-
-  /* Generate a subroutine to run when the results from select B
-  ** are exhausted and only data in select A remains.
-  */
-  if( op==TK_INTERSECT ){
-    addrEofB = addrEofA;
-    if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
-  }else{  
-    VdbeNoopComment((v, "eof-B subroutine"));
-    addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
-    sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);
-    sqlite3VdbeGoto(v, addrEofB);
-  }
-
-  /* Generate code to handle the case of A<B
-  */
-  VdbeNoopComment((v, "A-lt-B subroutine"));
-  addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
-  sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
-  sqlite3VdbeGoto(v, labelCmpr);
-
-  /* Generate code to handle the case of A==B
-  */
-  if( op==TK_ALL ){
-    addrAeqB = addrAltB;
-  }else if( op==TK_INTERSECT ){
-    addrAeqB = addrAltB;
-    addrAltB++;
-  }else{
-    VdbeNoopComment((v, "A-eq-B subroutine"));
-    addrAeqB =
-    sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
-    sqlite3VdbeGoto(v, labelCmpr);
-  }
-
-  /* Generate code to handle the case of A>B
-  */
-  VdbeNoopComment((v, "A-gt-B subroutine"));
-  addrAgtB = sqlite3VdbeCurrentAddr(v);
-  if( op==TK_ALL || op==TK_UNION ){
-    sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
-  }
-  sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
-  sqlite3VdbeGoto(v, labelCmpr);
-
-  /* This code runs once to initialize everything.
-  */
-  sqlite3VdbeJumpHere(v, addr1);
-  sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);
-  sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
-
-  /* Implement the main merge loop
-  */
-  sqlite3VdbeResolveLabel(v, labelCmpr);
-  sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
-  sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
-                         (char*)pKeyMerge, P4_KEYINFO);
-  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
-  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);
-
-  /* Jump to the this point in order to terminate the query.
-  */
-  sqlite3VdbeResolveLabel(v, labelEnd);
-
-  /* Set the number of output columns
-  */
-  if( pDest->eDest==SRT_Output ){
-    Select *pFirst = pPrior;
-    while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-    generateColumnNames(pParse, 0, pFirst->pEList);
-  }
-
-  /* Reassembly the compound query so that it will be freed correctly
-  ** by the calling function */
-  if( p->pPrior ){
-    sqlite3SelectDelete(db, p->pPrior);
-  }
-  p->pPrior = pPrior;
-  pPrior->pNext = p;
-
-  /*** TBD:  Insert subroutine calls to close cursors on incomplete
-  **** subqueries ****/
-  explainComposite(pParse, p->op, iSub1, iSub2, 0);
-  return pParse->nErr!=0;
-}
-#endif
-
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-/* Forward Declarations */
-static void substExprList(sqlite3*, ExprList*, int, ExprList*);
-static void substSelect(sqlite3*, Select *, int, ExprList*, int);
-
-/*
-** Scan through the expression pExpr.  Replace every reference to
-** a column in table number iTable with a copy of the iColumn-th
-** entry in pEList.  (But leave references to the ROWID column 
-** unchanged.)
-**
-** This routine is part of the flattening procedure.  A subquery
-** whose result set is defined by pEList appears as entry in the
-** FROM clause of a SELECT such that the VDBE cursor assigned to that
-** FORM clause entry is iTable.  This routine make the necessary 
-** changes to pExpr so that it refers directly to the source table
-** of the subquery rather the result set of the subquery.
-*/
-static Expr *substExpr(
-  sqlite3 *db,        /* Report malloc errors to this connection */
-  Expr *pExpr,        /* Expr in which substitution occurs */
-  int iTable,         /* Table to be substituted */
-  ExprList *pEList    /* Substitute expressions */
-){
-  if( pExpr==0 ) return 0;
-  if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
-    if( pExpr->iColumn<0 ){
-      pExpr->op = TK_NULL;
-    }else{
-      Expr *pNew;
-      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
-      assert( pExpr->pLeft==0 && pExpr->pRight==0 );
-      pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0);
-      sqlite3ExprDelete(db, pExpr);
-      pExpr = pNew;
-    }
-  }else{
-    pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList);
-    pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList);
-    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      substSelect(db, pExpr->x.pSelect, iTable, pEList, 1);
-    }else{
-      substExprList(db, pExpr->x.pList, iTable, pEList);
-    }
-  }
-  return pExpr;
-}
-static void substExprList(
-  sqlite3 *db,         /* Report malloc errors here */
-  ExprList *pList,     /* List to scan and in which to make substitutes */
-  int iTable,          /* Table to be substituted */
-  ExprList *pEList     /* Substitute values */
-){
-  int i;
-  if( pList==0 ) return;
-  for(i=0; i<pList->nExpr; i++){
-    pList->a[i].pExpr = substExpr(db, pList->a[i].pExpr, iTable, pEList);
-  }
-}
-static void substSelect(
-  sqlite3 *db,         /* Report malloc errors here */
-  Select *p,           /* SELECT statement in which to make substitutions */
-  int iTable,          /* Table to be replaced */
-  ExprList *pEList,    /* Substitute values */
-  int doPrior          /* Do substitutes on p->pPrior too */
-){
-  SrcList *pSrc;
-  struct SrcList_item *pItem;
-  int i;
-  if( !p ) return;
-  do{
-    substExprList(db, p->pEList, iTable, pEList);
-    substExprList(db, p->pGroupBy, iTable, pEList);
-    substExprList(db, p->pOrderBy, iTable, pEList);
-    p->pHaving = substExpr(db, p->pHaving, iTable, pEList);
-    p->pWhere = substExpr(db, p->pWhere, iTable, pEList);
-    pSrc = p->pSrc;
-    assert( pSrc!=0 );
-    for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
-      substSelect(db, pItem->pSelect, iTable, pEList, 1);
-      if( pItem->fg.isTabFunc ){
-        substExprList(db, pItem->u1.pFuncArg, iTable, pEList);
-      }
-    }
-  }while( doPrior && (p = p->pPrior)!=0 );
-}
-#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
-
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-/*
-** This routine attempts to flatten subqueries as a performance optimization.
-** This routine returns 1 if it makes changes and 0 if no flattening occurs.
-**
-** To understand the concept of flattening, consider the following
-** query:
-**
-**     SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
-**
-** The default way of implementing this query is to execute the
-** subquery first and store the results in a temporary table, then
-** run the outer query on that temporary table.  This requires two
-** passes over the data.  Furthermore, because the temporary table
-** has no indices, the WHERE clause on the outer query cannot be
-** optimized.
-**
-** This routine attempts to rewrite queries such as the above into
-** a single flat select, like this:
-**
-**     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
-**
-** The code generated for this simplification gives the same result
-** but only has to scan the data once.  And because indices might 
-** exist on the table t1, a complete scan of the data might be
-** avoided.
-**
-** Flattening is only attempted if all of the following are true:
-**
-**   (1)  The subquery and the outer query do not both use aggregates.
-**
-**   (2)  The subquery is not an aggregate or (2a) the outer query is not a join
-**        and (2b) the outer query does not use subqueries other than the one
-**        FROM-clause subquery that is a candidate for flattening.  (2b is
-**        due to ticket [2f7170d73bf9abf80] from 2015-02-09.)
-**
-**   (3)  The subquery is not the right operand of a left outer join
-**        (Originally ticket #306.  Strengthened by ticket #3300)
-**
-**   (4)  The subquery is not DISTINCT.
-**
-**  (**)  At one point restrictions (4) and (5) defined a subset of DISTINCT
-**        sub-queries that were excluded from this optimization. Restriction 
-**        (4) has since been expanded to exclude all DISTINCT subqueries.
-**
-**   (6)  The subquery does not use aggregates or the outer query is not
-**        DISTINCT.
-**
-**   (7)  The subquery has a FROM clause.  TODO:  For subqueries without
-**        A FROM clause, consider adding a FROM close with the special
-**        table sqlite_once that consists of a single row containing a
-**        single NULL.
-**
-**   (8)  The subquery does not use LIMIT or the outer query is not a join.
-**
-**   (9)  The subquery does not use LIMIT or the outer query does not use
-**        aggregates.
-**
-**  (**)  Restriction (10) was removed from the code on 2005-02-05 but we
-**        accidently carried the comment forward until 2014-09-15.  Original
-**        text: "The subquery does not use aggregates or the outer query 
-**        does not use LIMIT."
-**
-**  (11)  The subquery and the outer query do not both have ORDER BY clauses.
-**
-**  (**)  Not implemented.  Subsumed into restriction (3).  Was previously
-**        a separate restriction deriving from ticket #350.
-**
-**  (13)  The subquery and outer query do not both use LIMIT.
-**
-**  (14)  The subquery does not use OFFSET.
-**
-**  (15)  The outer query is not part of a compound select or the
-**        subquery does not have a LIMIT clause.
-**        (See ticket #2339 and ticket [02a8e81d44]).
-**
-**  (16)  The outer query is not an aggregate or the subquery does
-**        not contain ORDER BY.  (Ticket #2942)  This used to not matter
-**        until we introduced the group_concat() function.  
-**
-**  (17)  The sub-query is not a compound select, or it is a UNION ALL 
-**        compound clause made up entirely of non-aggregate queries, and 
-**        the parent query:
-**
-**          * is not itself part of a compound select,
-**          * is not an aggregate or DISTINCT query, and
-**          * is not a join
-**
-**        The parent and sub-query may contain WHERE clauses. Subject to
-**        rules (11), (13) and (14), they may also contain ORDER BY,
-**        LIMIT and OFFSET clauses.  The subquery cannot use any compound
-**        operator other than UNION ALL because all the other compound
-**        operators have an implied DISTINCT which is disallowed by
-**        restriction (4).
-**
-**        Also, each component of the sub-query must return the same number
-**        of result columns. This is actually a requirement for any compound
-**        SELECT statement, but all the code here does is make sure that no
-**        such (illegal) sub-query is flattened. The caller will detect the
-**        syntax error and return a detailed message.
-**
-**  (18)  If the sub-query is a compound select, then all terms of the
-**        ORDER by clause of the parent must be simple references to 
-**        columns of the sub-query.
-**
-**  (19)  The subquery does not use LIMIT or the outer query does not
-**        have a WHERE clause.
-**
-**  (20)  If the sub-query is a compound select, then it must not use
-**        an ORDER BY clause.  Ticket #3773.  We could relax this constraint
-**        somewhat by saying that the terms of the ORDER BY clause must
-**        appear as unmodified result columns in the outer query.  But we
-**        have other optimizations in mind to deal with that case.
-**
-**  (21)  The subquery does not use LIMIT or the outer query is not
-**        DISTINCT.  (See ticket [752e1646fc]).
-**
-**  (22)  The subquery is not a recursive CTE.
-**
-**  (23)  The parent is not a recursive CTE, or the sub-query is not a
-**        compound query. This restriction is because transforming the
-**        parent to a compound query confuses the code that handles
-**        recursive queries in multiSelect().
-**
-**  (24)  The subquery is not an aggregate that uses the built-in min() or 
-**        or max() functions.  (Without this restriction, a query like:
-**        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
-**        return the value X for which Y was maximal.)
-**
-**
-** In this routine, the "p" parameter is a pointer to the outer query.
-** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
-** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
-**
-** If flattening is not attempted, this routine is a no-op and returns 0.
-** If flattening is attempted this routine returns 1.
-**
-** All of the expression analysis must occur on both the outer query and
-** the subquery before this routine runs.
-*/
-static int flattenSubquery(
-  Parse *pParse,       /* Parsing context */
-  Select *p,           /* The parent or outer SELECT statement */
-  int iFrom,           /* Index in p->pSrc->a[] of the inner subquery */
-  int isAgg,           /* True if outer SELECT uses aggregate functions */
-  int subqueryIsAgg    /* True if the subquery uses aggregate functions */
-){
-  const char *zSavedAuthContext = pParse->zAuthContext;
-  Select *pParent;    /* Current UNION ALL term of the other query */
-  Select *pSub;       /* The inner query or "subquery" */
-  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
-  SrcList *pSrc;      /* The FROM clause of the outer query */
-  SrcList *pSubSrc;   /* The FROM clause of the subquery */
-  ExprList *pList;    /* The result set of the outer query */
-  int iParent;        /* VDBE cursor number of the pSub result set temp table */
-  int i;              /* Loop counter */
-  Expr *pWhere;                    /* The WHERE clause */
-  struct SrcList_item *pSubitem;   /* The subquery */
-  sqlite3 *db = pParse->db;
-
-  /* Check to see if flattening is permitted.  Return 0 if not.
-  */
-  assert( p!=0 );
-  assert( p->pPrior==0 );  /* Unable to flatten compound queries */
-  if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
-  pSrc = p->pSrc;
-  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
-  pSubitem = &pSrc->a[iFrom];
-  iParent = pSubitem->iCursor;
-  pSub = pSubitem->pSelect;
-  assert( pSub!=0 );
-  if( subqueryIsAgg ){
-    if( isAgg ) return 0;                                /* Restriction (1)   */
-    if( pSrc->nSrc>1 ) return 0;                         /* Restriction (2a)  */
-    if( (p->pWhere && ExprHasProperty(p->pWhere,EP_Subquery))
-     || (sqlite3ExprListFlags(p->pEList) & EP_Subquery)!=0
-     || (sqlite3ExprListFlags(p->pOrderBy) & EP_Subquery)!=0
-    ){
-      return 0;                                          /* Restriction (2b)  */
-    }
-  }
-    
-  pSubSrc = pSub->pSrc;
-  assert( pSubSrc );
-  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
-  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
-  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
-  ** became arbitrary expressions, we were forced to add restrictions (13)
-  ** and (14). */
-  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
-  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
-  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
-    return 0;                                            /* Restriction (15) */
-  }
-  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
-  if( pSub->selFlags & SF_Distinct ) return 0;           /* Restriction (5)  */
-  if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
-     return 0;         /* Restrictions (8)(9) */
-  }
-  if( (p->selFlags & SF_Distinct)!=0 && subqueryIsAgg ){
-     return 0;         /* Restriction (6)  */
-  }
-  if( p->pOrderBy && pSub->pOrderBy ){
-     return 0;                                           /* Restriction (11) */
-  }
-  if( isAgg && pSub->pOrderBy ) return 0;                /* Restriction (16) */
-  if( pSub->pLimit && p->pWhere ) return 0;              /* Restriction (19) */
-  if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
-     return 0;         /* Restriction (21) */
-  }
-  testcase( pSub->selFlags & SF_Recursive );
-  testcase( pSub->selFlags & SF_MinMaxAgg );
-  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
-    return 0; /* Restrictions (22) and (24) */
-  }
-  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
-    return 0; /* Restriction (23) */
-  }
-
-  /* OBSOLETE COMMENT 1:
-  ** Restriction 3:  If the subquery is a join, make sure the subquery is 
-  ** not used as the right operand of an outer join.  Examples of why this
-  ** is not allowed:
-  **
-  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
-  **
-  ** If we flatten the above, we would get
-  **
-  **         (t1 LEFT OUTER JOIN t2) JOIN t3
-  **
-  ** which is not at all the same thing.
-  **
-  ** OBSOLETE COMMENT 2:
-  ** Restriction 12:  If the subquery is the right operand of a left outer
-  ** join, make sure the subquery has no WHERE clause.
-  ** An examples of why this is not allowed:
-  **
-  **         t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
-  **
-  ** If we flatten the above, we would get
-  **
-  **         (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
-  **
-  ** But the t2.x>0 test will always fail on a NULL row of t2, which
-  ** effectively converts the OUTER JOIN into an INNER JOIN.
-  **
-  ** THIS OVERRIDES OBSOLETE COMMENTS 1 AND 2 ABOVE:
-  ** Ticket #3300 shows that flattening the right term of a LEFT JOIN
-  ** is fraught with danger.  Best to avoid the whole thing.  If the
-  ** subquery is the right term of a LEFT JOIN, then do not flatten.
-  */
-  if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
-    return 0;
-  }
-
-  /* Restriction 17: If the sub-query is a compound SELECT, then it must
-  ** use only the UNION ALL operator. And none of the simple select queries
-  ** that make up the compound SELECT are allowed to be aggregate or distinct
-  ** queries.
-  */
-  if( pSub->pPrior ){
-    if( pSub->pOrderBy ){
-      return 0;  /* Restriction 20 */
-    }
-    if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
-      return 0;
-    }
-    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
-      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
-      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
-      assert( pSub->pSrc!=0 );
-      assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
-      if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0
-       || (pSub1->pPrior && pSub1->op!=TK_ALL) 
-       || pSub1->pSrc->nSrc<1
-      ){
-        return 0;
-      }
-      testcase( pSub1->pSrc->nSrc>1 );
-    }
-
-    /* Restriction 18. */
-    if( p->pOrderBy ){
-      int ii;
-      for(ii=0; ii<p->pOrderBy->nExpr; ii++){
-        if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;
-      }
-    }
-  }
-
-  /***** If we reach this point, flattening is permitted. *****/
-  SELECTTRACE(1,pParse,p,("flatten %s.%p from term %d\n",
-                   pSub->zSelName, pSub, iFrom));
-
-  /* Authorize the subquery */
-  pParse->zAuthContext = pSubitem->zName;
-  TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
-  testcase( i==SQLITE_DENY );
-  pParse->zAuthContext = zSavedAuthContext;
-
-  /* If the sub-query is a compound SELECT statement, then (by restrictions
-  ** 17 and 18 above) it must be a UNION ALL and the parent query must 
-  ** be of the form:
-  **
-  **     SELECT <expr-list> FROM (<sub-query>) <where-clause> 
-  **
-  ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block
-  ** creates N-1 copies of the parent query without any ORDER BY, LIMIT or 
-  ** OFFSET clauses and joins them to the left-hand-side of the original
-  ** using UNION ALL operators. In this case N is the number of simple
-  ** select statements in the compound sub-query.
-  **
-  ** Example:
-  **
-  **     SELECT a+1 FROM (
-  **        SELECT x FROM tab
-  **        UNION ALL
-  **        SELECT y FROM tab
-  **        UNION ALL
-  **        SELECT abs(z*2) FROM tab2
-  **     ) WHERE a!=5 ORDER BY 1
-  **
-  ** Transformed into:
-  **
-  **     SELECT x+1 FROM tab WHERE x+1!=5
-  **     UNION ALL
-  **     SELECT y+1 FROM tab WHERE y+1!=5
-  **     UNION ALL
-  **     SELECT abs(z*2)+1 FROM tab2 WHERE abs(z*2)+1!=5
-  **     ORDER BY 1
-  **
-  ** We call this the "compound-subquery flattening".
-  */
-  for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
-    Select *pNew;
-    ExprList *pOrderBy = p->pOrderBy;
-    Expr *pLimit = p->pLimit;
-    Expr *pOffset = p->pOffset;
-    Select *pPrior = p->pPrior;
-    p->pOrderBy = 0;
-    p->pSrc = 0;
-    p->pPrior = 0;
-    p->pLimit = 0;
-    p->pOffset = 0;
-    pNew = sqlite3SelectDup(db, p, 0);
-    sqlite3SelectSetName(pNew, pSub->zSelName);
-    p->pOffset = pOffset;
-    p->pLimit = pLimit;
-    p->pOrderBy = pOrderBy;
-    p->pSrc = pSrc;
-    p->op = TK_ALL;
-    if( pNew==0 ){
-      p->pPrior = pPrior;
-    }else{
-      pNew->pPrior = pPrior;
-      if( pPrior ) pPrior->pNext = pNew;
-      pNew->pNext = p;
-      p->pPrior = pNew;
-      SELECTTRACE(2,pParse,p,
-         ("compound-subquery flattener creates %s.%p as peer\n",
-         pNew->zSelName, pNew));
-    }
-    if( db->mallocFailed ) return 1;
-  }
-
-  /* Begin flattening the iFrom-th entry of the FROM clause 
-  ** in the outer query.
-  */
-  pSub = pSub1 = pSubitem->pSelect;
-
-  /* Delete the transient table structure associated with the
-  ** subquery
-  */
-  sqlite3DbFree(db, pSubitem->zDatabase);
-  sqlite3DbFree(db, pSubitem->zName);
-  sqlite3DbFree(db, pSubitem->zAlias);
-  pSubitem->zDatabase = 0;
-  pSubitem->zName = 0;
-  pSubitem->zAlias = 0;
-  pSubitem->pSelect = 0;
-
-  /* Defer deleting the Table object associated with the
-  ** subquery until code generation is
-  ** complete, since there may still exist Expr.pTab entries that
-  ** refer to the subquery even after flattening.  Ticket #3346.
-  **
-  ** pSubitem->pTab is always non-NULL by test restrictions and tests above.
-  */
-  if( ALWAYS(pSubitem->pTab!=0) ){
-    Table *pTabToDel = pSubitem->pTab;
-    if( pTabToDel->nRef==1 ){
-      Parse *pToplevel = sqlite3ParseToplevel(pParse);
-      pTabToDel->pNextZombie = pToplevel->pZombieTab;
-      pToplevel->pZombieTab = pTabToDel;
-    }else{
-      pTabToDel->nRef--;
-    }
-    pSubitem->pTab = 0;
-  }
-
-  /* The following loop runs once for each term in a compound-subquery
-  ** flattening (as described above).  If we are doing a different kind
-  ** of flattening - a flattening other than a compound-subquery flattening -
-  ** then this loop only runs once.
-  **
-  ** This loop moves all of the FROM elements of the subquery into the
-  ** the FROM clause of the outer query.  Before doing this, remember
-  ** the cursor number for the original outer query FROM element in
-  ** iParent.  The iParent cursor will never be used.  Subsequent code
-  ** will scan expressions looking for iParent references and replace
-  ** those references with expressions that resolve to the subquery FROM
-  ** elements we are now copying in.
-  */
-  for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
-    int nSubSrc;
-    u8 jointype = 0;
-    pSubSrc = pSub->pSrc;     /* FROM clause of subquery */
-    nSubSrc = pSubSrc->nSrc;  /* Number of terms in subquery FROM clause */
-    pSrc = pParent->pSrc;     /* FROM clause of the outer query */
-
-    if( pSrc ){
-      assert( pParent==p );  /* First time through the loop */
-      jointype = pSubitem->fg.jointype;
-    }else{
-      assert( pParent!=p );  /* 2nd and subsequent times through the loop */
-      pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
-      if( pSrc==0 ){
-        assert( db->mallocFailed );
-        break;
-      }
-    }
-
-    /* The subquery uses a single slot of the FROM clause of the outer
-    ** query.  If the subquery has more than one element in its FROM clause,
-    ** then expand the outer query to make space for it to hold all elements
-    ** of the subquery.
-    **
-    ** Example:
-    **
-    **    SELECT * FROM tabA, (SELECT * FROM sub1, sub2), tabB;
-    **
-    ** The outer query has 3 slots in its FROM clause.  One slot of the
-    ** outer query (the middle slot) is used by the subquery.  The next
-    ** block of code will expand the outer query FROM clause to 4 slots.
-    ** The middle slot is expanded to two slots in order to make space
-    ** for the two elements in the FROM clause of the subquery.
-    */
-    if( nSubSrc>1 ){
-      pParent->pSrc = pSrc = sqlite3SrcListEnlarge(db, pSrc, nSubSrc-1,iFrom+1);
-      if( db->mallocFailed ){
-        break;
-      }
-    }
-
-    /* Transfer the FROM clause terms from the subquery into the
-    ** outer query.
-    */
-    for(i=0; i<nSubSrc; i++){
-      sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
-      pSrc->a[i+iFrom] = pSubSrc->a[i];
-      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
-    }
-    pSrc->a[iFrom].fg.jointype = jointype;
-  
-    /* Now begin substituting subquery result set expressions for 
-    ** references to the iParent in the outer query.
-    ** 
-    ** Example:
-    **
-    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
-    **   \                     \_____________ subquery __________/          /
-    **    \_____________________ outer query ______________________________/
-    **
-    ** We look at every expression in the outer query and every place we see
-    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
-    */
-    pList = pParent->pEList;
-    for(i=0; i<pList->nExpr; i++){
-      if( pList->a[i].zName==0 ){
-        char *zName = sqlite3DbStrDup(db, pList->a[i].zSpan);
-        sqlite3Dequote(zName);
-        pList->a[i].zName = zName;
-      }
-    }
-    if( pSub->pOrderBy ){
-      /* At this point, any non-zero iOrderByCol values indicate that the
-      ** ORDER BY column expression is identical to the iOrderByCol'th
-      ** expression returned by SELECT statement pSub. Since these values
-      ** do not necessarily correspond to columns in SELECT statement pParent,
-      ** zero them before transfering the ORDER BY clause.
-      **
-      ** Not doing this may cause an error if a subsequent call to this
-      ** function attempts to flatten a compound sub-query into pParent
-      ** (the only way this can happen is if the compound sub-query is
-      ** currently part of pSub->pSrc). See ticket [d11a6e908f].  */
-      ExprList *pOrderBy = pSub->pOrderBy;
-      for(i=0; i<pOrderBy->nExpr; i++){
-        pOrderBy->a[i].u.x.iOrderByCol = 0;
-      }
-      assert( pParent->pOrderBy==0 );
-      assert( pSub->pPrior==0 );
-      pParent->pOrderBy = pOrderBy;
-      pSub->pOrderBy = 0;
-    }
-    pWhere = sqlite3ExprDup(db, pSub->pWhere, 0);
-    if( subqueryIsAgg ){
-      assert( pParent->pHaving==0 );
-      pParent->pHaving = pParent->pWhere;
-      pParent->pWhere = pWhere;
-      pParent->pHaving = sqlite3ExprAnd(db, pParent->pHaving, 
-                                  sqlite3ExprDup(db, pSub->pHaving, 0));
-      assert( pParent->pGroupBy==0 );
-      pParent->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy, 0);
-    }else{
-      pParent->pWhere = sqlite3ExprAnd(db, pParent->pWhere, pWhere);
-    }
-    substSelect(db, pParent, iParent, pSub->pEList, 0);
-  
-    /* The flattened query is distinct if either the inner or the
-    ** outer query is distinct. 
-    */
-    pParent->selFlags |= pSub->selFlags & SF_Distinct;
-  
-    /*
-    ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
-    **
-    ** One is tempted to try to add a and b to combine the limits.  But this
-    ** does not work if either limit is negative.
-    */
-    if( pSub->pLimit ){
-      pParent->pLimit = pSub->pLimit;
-      pSub->pLimit = 0;
-    }
-  }
-
-  /* Finially, delete what is left of the subquery and return
-  ** success.
-  */
-  sqlite3SelectDelete(db, pSub1);
-
-#if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x100 ){
-    SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
-    sqlite3TreeViewSelect(0, p, 0);
-  }
-#endif
-
-  return 1;
-}
-#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
-
-
-
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-/*
-** Make copies of relevant WHERE clause terms of the outer query into
-** the WHERE clause of subquery.  Example:
-**
-**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
-**
-** Transformed into:
-**
-**    SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
-**     WHERE x=5 AND y=10;
-**
-** The hope is that the terms added to the inner query will make it more
-** efficient.
-**
-** Do not attempt this optimization if:
-**
-**   (1) The inner query is an aggregate.  (In that case, we'd really want
-**       to copy the outer WHERE-clause terms onto the HAVING clause of the
-**       inner query.  But they probably won't help there so do not bother.)
-**
-**   (2) The inner query is the recursive part of a common table expression.
-**
-**   (3) The inner query has a LIMIT clause (since the changes to the WHERE
-**       close would change the meaning of the LIMIT).
-**
-**   (4) The inner query is the right operand of a LEFT JOIN.  (The caller
-**       enforces this restriction since this routine does not have enough
-**       information to know.)
-**
-**   (5) The WHERE clause expression originates in the ON or USING clause
-**       of a LEFT JOIN.
-**
-** Return 0 if no changes are made and non-zero if one or more WHERE clause
-** terms are duplicated into the subquery.
-*/
-static int pushDownWhereTerms(
-  sqlite3 *db,          /* The database connection (for malloc()) */
-  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
-  Expr *pWhere,         /* The WHERE clause of the outer query */
-  int iCursor           /* Cursor number of the subquery */
-){
-  Expr *pNew;
-  int nChng = 0;
-  if( pWhere==0 ) return 0;
-  if( (pSubq->selFlags & (SF_Aggregate|SF_Recursive))!=0 ){
-     return 0; /* restrictions (1) and (2) */
-  }
-  if( pSubq->pLimit!=0 ){
-     return 0; /* restriction (3) */
-  }
-  while( pWhere->op==TK_AND ){
-    nChng += pushDownWhereTerms(db, pSubq, pWhere->pRight, iCursor);
-    pWhere = pWhere->pLeft;
-  }
-  if( ExprHasProperty(pWhere,EP_FromJoin) ) return 0; /* restriction 5 */
-  if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
-    nChng++;
-    while( pSubq ){
-      pNew = sqlite3ExprDup(db, pWhere, 0);
-      pNew = substExpr(db, pNew, iCursor, pSubq->pEList);
-      pSubq->pWhere = sqlite3ExprAnd(db, pSubq->pWhere, pNew);
-      pSubq = pSubq->pPrior;
-    }
-  }
-  return nChng;
-}
-#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
-
-/*
-** Based on the contents of the AggInfo structure indicated by the first
-** argument, this function checks if the following are true:
-**
-**    * the query contains just a single aggregate function,
-**    * the aggregate function is either min() or max(), and
-**    * the argument to the aggregate function is a column value.
-**
-** If all of the above are true, then WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX
-** is returned as appropriate. Also, *ppMinMax is set to point to the 
-** list of arguments passed to the aggregate before returning.
-**
-** Or, if the conditions above are not met, *ppMinMax is set to 0 and
-** WHERE_ORDERBY_NORMAL is returned.
-*/
-static u8 minMaxQuery(AggInfo *pAggInfo, ExprList **ppMinMax){
-  int eRet = WHERE_ORDERBY_NORMAL;          /* Return value */
-
-  *ppMinMax = 0;
-  if( pAggInfo->nFunc==1 ){
-    Expr *pExpr = pAggInfo->aFunc[0].pExpr; /* Aggregate function */
-    ExprList *pEList = pExpr->x.pList;      /* Arguments to agg function */
-
-    assert( pExpr->op==TK_AGG_FUNCTION );
-    if( pEList && pEList->nExpr==1 && pEList->a[0].pExpr->op==TK_AGG_COLUMN ){
-      const char *zFunc = pExpr->u.zToken;
-      if( sqlite3StrICmp(zFunc, "min")==0 ){
-        eRet = WHERE_ORDERBY_MIN;
-        *ppMinMax = pEList;
-      }else if( sqlite3StrICmp(zFunc, "max")==0 ){
-        eRet = WHERE_ORDERBY_MAX;
-        *ppMinMax = pEList;
-      }
-    }
-  }
-
-  assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 );
-  return eRet;
-}
-
-/*
-** The select statement passed as the first argument is an aggregate query.
-** The second argument is the associated aggregate-info object. This 
-** function tests if the SELECT is of the form:
-**
-**   SELECT count(*) FROM <tbl>
-**
-** where table is a database table, not a sub-select or view. If the query
-** does match this pattern, then a pointer to the Table object representing
-** <tbl> is returned. Otherwise, 0 is returned.
-*/
-static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
-  Table *pTab;
-  Expr *pExpr;
-
-  assert( !p->pGroupBy );
-
-  if( p->pWhere || p->pEList->nExpr!=1 
-   || p->pSrc->nSrc!=1 || p->pSrc->a[0].pSelect
-  ){
-    return 0;
-  }
-  pTab = p->pSrc->a[0].pTab;
-  pExpr = p->pEList->a[0].pExpr;
-  assert( pTab && !pTab->pSelect && pExpr );
-
-  if( IsVirtual(pTab) ) return 0;
-  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
-  if( NEVER(pAggInfo->nFunc==0) ) return 0;
-  if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
-  if( pExpr->flags&EP_Distinct ) return 0;
-
-  return pTab;
-}
-
-/*
-** If the source-list item passed as an argument was augmented with an
-** INDEXED BY clause, then try to locate the specified index. If there
-** was such a clause and the named index cannot be found, return 
-** SQLITE_ERROR and leave an error in pParse. Otherwise, populate 
-** pFrom->pIndex and return SQLITE_OK.
-*/
-int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
-  if( pFrom->pTab && pFrom->fg.isIndexedBy ){
-    Table *pTab = pFrom->pTab;
-    char *zIndexedBy = pFrom->u1.zIndexedBy;
-    Index *pIdx;
-    for(pIdx=pTab->pIndex; 
-        pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); 
-        pIdx=pIdx->pNext
-    );
-    if( !pIdx ){
-      sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
-      pParse->checkSchema = 1;
-      return SQLITE_ERROR;
-    }
-    pFrom->pIBIndex = pIdx;
-  }
-  return SQLITE_OK;
-}
-/*
-** Detect compound SELECT statements that use an ORDER BY clause with 
-** an alternative collating sequence.
-**
-**    SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...
-**
-** These are rewritten as a subquery:
-**
-**    SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)
-**     ORDER BY ... COLLATE ...
-**
-** This transformation is necessary because the multiSelectOrderBy() routine
-** above that generates the code for a compound SELECT with an ORDER BY clause
-** uses a merge algorithm that requires the same collating sequence on the
-** result columns as on the ORDER BY clause.  See ticket
-** http://www.sqlite.org/src/info/6709574d2a
-**
-** This transformation is only needed for EXCEPT, INTERSECT, and UNION.
-** The UNION ALL operator works fine with multiSelectOrderBy() even when
-** there are COLLATE terms in the ORDER BY.
-*/
-static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
-  int i;
-  Select *pNew;
-  Select *pX;
-  sqlite3 *db;
-  struct ExprList_item *a;
-  SrcList *pNewSrc;
-  Parse *pParse;
-  Token dummy;
-
-  if( p->pPrior==0 ) return WRC_Continue;
-  if( p->pOrderBy==0 ) return WRC_Continue;
-  for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
-  if( pX==0 ) return WRC_Continue;
-  a = p->pOrderBy->a;
-  for(i=p->pOrderBy->nExpr-1; i>=0; i--){
-    if( a[i].pExpr->flags & EP_Collate ) break;
-  }
-  if( i<0 ) return WRC_Continue;
-
-  /* If we reach this point, that means the transformation is required. */
-
-  pParse = pWalker->pParse;
-  db = pParse->db;
-  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
-  if( pNew==0 ) return WRC_Abort;
-  memset(&dummy, 0, sizeof(dummy));
-  pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);
-  if( pNewSrc==0 ) return WRC_Abort;
-  *pNew = *p;
-  p->pSrc = pNewSrc;
-  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ALL, 0));
-  p->op = TK_SELECT;
-  p->pWhere = 0;
-  pNew->pGroupBy = 0;
-  pNew->pHaving = 0;
-  pNew->pOrderBy = 0;
-  p->pPrior = 0;
-  p->pNext = 0;
-  p->pWith = 0;
-  p->selFlags &= ~SF_Compound;
-  assert( (p->selFlags & SF_Converted)==0 );
-  p->selFlags |= SF_Converted;
-  assert( pNew->pPrior!=0 );
-  pNew->pPrior->pNext = pNew;
-  pNew->pLimit = 0;
-  pNew->pOffset = 0;
-  return WRC_Continue;
-}
-
-#ifndef SQLITE_OMIT_CTE
-/*
-** Argument pWith (which may be NULL) points to a linked list of nested 
-** WITH contexts, from inner to outermost. If the table identified by 
-** FROM clause element pItem is really a common-table-expression (CTE) 
-** then return a pointer to the CTE definition for that table. Otherwise
-** return NULL.
-**
-** If a non-NULL value is returned, set *ppContext to point to the With
-** object that the returned CTE belongs to.
-*/
-static struct Cte *searchWith(
-  With *pWith,                    /* Current outermost WITH clause */
-  struct SrcList_item *pItem,     /* FROM clause element to resolve */
-  With **ppContext                /* OUT: WITH clause return value belongs to */
-){
-  const char *zName;
-  if( pItem->zDatabase==0 && (zName = pItem->zName)!=0 ){
-    With *p;
-    for(p=pWith; p; p=p->pOuter){
-      int i;
-      for(i=0; i<p->nCte; i++){
-        if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){
-          *ppContext = p;
-          return &p->a[i];
-        }
-      }
-    }
-  }
-  return 0;
-}
-
-/* The code generator maintains a stack of active WITH clauses
-** with the inner-most WITH clause being at the top of the stack.
-**
-** This routine pushes the WITH clause passed as the second argument
-** onto the top of the stack. If argument bFree is true, then this
-** WITH clause will never be popped from the stack. In this case it
-** should be freed along with the Parse object. In other cases, when
-** bFree==0, the With object will be freed along with the SELECT 
-** statement with which it is associated.
-*/
-void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){
-  assert( bFree==0 || pParse->pWith==0 );
-  if( pWith ){
-    pWith->pOuter = pParse->pWith;
-    pParse->pWith = pWith;
-    pParse->bFreeWith = bFree;
-  }
-}
-
-/*
-** This function checks if argument pFrom refers to a CTE declared by 
-** a WITH clause on the stack currently maintained by the parser. And,
-** if currently processing a CTE expression, if it is a recursive
-** reference to the current CTE.
-**
-** If pFrom falls into either of the two categories above, pFrom->pTab
-** and other fields are populated accordingly. The caller should check
-** (pFrom->pTab!=0) to determine whether or not a successful match
-** was found.
-**
-** Whether or not a match is found, SQLITE_OK is returned if no error
-** occurs. If an error does occur, an error message is stored in the
-** parser and some error code other than SQLITE_OK returned.
-*/
-static int withExpand(
-  Walker *pWalker, 
-  struct SrcList_item *pFrom
-){
-  Parse *pParse = pWalker->pParse;
-  sqlite3 *db = pParse->db;
-  struct Cte *pCte;               /* Matched CTE (or NULL if no match) */
-  With *pWith;                    /* WITH clause that pCte belongs to */
-
-  assert( pFrom->pTab==0 );
-
-  pCte = searchWith(pParse->pWith, pFrom, &pWith);
-  if( pCte ){
-    Table *pTab;
-    ExprList *pEList;
-    Select *pSel;
-    Select *pLeft;                /* Left-most SELECT statement */
-    int bMayRecursive;            /* True if compound joined by UNION [ALL] */
-    With *pSavedWith;             /* Initial value of pParse->pWith */
-
-    /* If pCte->zCteErr is non-NULL at this point, then this is an illegal
-    ** recursive reference to CTE pCte. Leave an error in pParse and return
-    ** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
-    ** In this case, proceed.  */
-    if( pCte->zCteErr ){
-      sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
-      return SQLITE_ERROR;
-    }
-
-    assert( pFrom->pTab==0 );
-    pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
-    if( pTab==0 ) return WRC_Abort;
-    pTab->nRef = 1;
-    pTab->zName = sqlite3DbStrDup(db, pCte->zName);
-    pTab->iPKey = -1;
-    pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
-    pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
-    pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
-    if( db->mallocFailed ) return SQLITE_NOMEM;
-    assert( pFrom->pSelect );
-
-    /* Check if this is a recursive CTE. */
-    pSel = pFrom->pSelect;
-    bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
-    if( bMayRecursive ){
-      int i;
-      SrcList *pSrc = pFrom->pSelect->pSrc;
-      for(i=0; i<pSrc->nSrc; i++){
-        struct SrcList_item *pItem = &pSrc->a[i];
-        if( pItem->zDatabase==0 
-         && pItem->zName!=0 
-         && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
-          ){
-          pItem->pTab = pTab;
-          pItem->fg.isRecursive = 1;
-          pTab->nRef++;
-          pSel->selFlags |= SF_Recursive;
-        }
-      }
-    }
-
-    /* Only one recursive reference is permitted. */ 
-    if( pTab->nRef>2 ){
-      sqlite3ErrorMsg(
-          pParse, "multiple references to recursive table: %s", pCte->zName
-      );
-      return SQLITE_ERROR;
-    }
-    assert( pTab->nRef==1 || ((pSel->selFlags&SF_Recursive) && pTab->nRef==2 ));
-
-    pCte->zCteErr = "circular reference: %s";
-    pSavedWith = pParse->pWith;
-    pParse->pWith = pWith;
-    sqlite3WalkSelect(pWalker, bMayRecursive ? pSel->pPrior : pSel);
-
-    for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);
-    pEList = pLeft->pEList;
-    if( pCte->pCols ){
-      if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){
-        sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",
-            pCte->zName, pEList->nExpr, pCte->pCols->nExpr
-        );
-        pParse->pWith = pSavedWith;
-        return SQLITE_ERROR;
-      }
-      pEList = pCte->pCols;
-    }
-
-    sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
-    if( bMayRecursive ){
-      if( pSel->selFlags & SF_Recursive ){
-        pCte->zCteErr = "multiple recursive references: %s";
-      }else{
-        pCte->zCteErr = "recursive reference in a subquery: %s";
-      }
-      sqlite3WalkSelect(pWalker, pSel);
-    }
-    pCte->zCteErr = 0;
-    pParse->pWith = pSavedWith;
-  }
-
-  return SQLITE_OK;
-}
-#endif
-
-#ifndef SQLITE_OMIT_CTE
-/*
-** If the SELECT passed as the second argument has an associated WITH 
-** clause, pop it from the stack stored as part of the Parse object.
-**
-** This function is used as the xSelectCallback2() callback by
-** sqlite3SelectExpand() when walking a SELECT tree to resolve table
-** names and other FROM clause elements. 
-*/
-static void selectPopWith(Walker *pWalker, Select *p){
-  Parse *pParse = pWalker->pParse;
-  With *pWith = findRightmost(p)->pWith;
-  if( pWith!=0 ){
-    assert( pParse->pWith==pWith );
-    pParse->pWith = pWith->pOuter;
-  }
-}
-#else
-#define selectPopWith 0
-#endif
-
-/*
-** This routine is a Walker callback for "expanding" a SELECT statement.
-** "Expanding" means to do the following:
-**
-**    (1)  Make sure VDBE cursor numbers have been assigned to every
-**         element of the FROM clause.
-**
-**    (2)  Fill in the pTabList->a[].pTab fields in the SrcList that 
-**         defines FROM clause.  When views appear in the FROM clause,
-**         fill pTabList->a[].pSelect with a copy of the SELECT statement
-**         that implements the view.  A copy is made of the view's SELECT
-**         statement so that we can freely modify or delete that statement
-**         without worrying about messing up the persistent representation
-**         of the view.
-**
-**    (3)  Add terms to the WHERE clause to accommodate the NATURAL keyword
-**         on joins and the ON and USING clause of joins.
-**
-**    (4)  Scan the list of columns in the result set (pEList) looking
-**         for instances of the "*" operator or the TABLE.* operator.
-**         If found, expand each "*" to be every column in every table
-**         and TABLE.* to be every column in TABLE.
-**
-*/
-static int selectExpander(Walker *pWalker, Select *p){
-  Parse *pParse = pWalker->pParse;
-  int i, j, k;
-  SrcList *pTabList;
-  ExprList *pEList;
-  struct SrcList_item *pFrom;
-  sqlite3 *db = pParse->db;
-  Expr *pE, *pRight, *pExpr;
-  u16 selFlags = p->selFlags;
-
-  p->selFlags |= SF_Expanded;
-  if( db->mallocFailed  ){
-    return WRC_Abort;
-  }
-  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
-    return WRC_Prune;
-  }
-  pTabList = p->pSrc;
-  pEList = p->pEList;
-  if( pWalker->xSelectCallback2==selectPopWith ){
-    sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
-  }
-
-  /* Make sure cursor numbers have been assigned to all entries in
-  ** the FROM clause of the SELECT statement.
-  */
-  sqlite3SrcListAssignCursors(pParse, pTabList);
-
-  /* Look up every table named in the FROM clause of the select.  If
-  ** an entry of the FROM clause is a subquery instead of a table or view,
-  ** then create a transient table structure to describe the subquery.
-  */
-  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-    Table *pTab;
-    assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
-    if( pFrom->fg.isRecursive ) continue;
-    assert( pFrom->pTab==0 );
-#ifndef SQLITE_OMIT_CTE
-    if( withExpand(pWalker, pFrom) ) return WRC_Abort;
-    if( pFrom->pTab ) {} else
-#endif
-    if( pFrom->zName==0 ){
-#ifndef SQLITE_OMIT_SUBQUERY
-      Select *pSel = pFrom->pSelect;
-      /* A sub-query in the FROM clause of a SELECT */
-      assert( pSel!=0 );
-      assert( pFrom->pTab==0 );
-      if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
-      pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
-      if( pTab==0 ) return WRC_Abort;
-      pTab->nRef = 1;
-      pTab->zName = sqlite3MPrintf(db, "sqlite_sq_%p", (void*)pTab);
-      while( pSel->pPrior ){ pSel = pSel->pPrior; }
-      sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
-      pTab->iPKey = -1;
-      pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
-      pTab->tabFlags |= TF_Ephemeral;
-#endif
-    }else{
-      /* An ordinary table or view name in the FROM clause */
-      assert( pFrom->pTab==0 );
-      pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
-      if( pTab==0 ) return WRC_Abort;
-      if( pTab->nRef==0xffff ){
-        sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
-           pTab->zName);
-        pFrom->pTab = 0;
-        return WRC_Abort;
-      }
-      pTab->nRef++;
-#if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
-      if( pTab->pSelect || IsVirtual(pTab) ){
-        i16 nCol;
-        if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
-        assert( pFrom->pSelect==0 );
-        if( pFrom->fg.isTabFunc && !IsVirtual(pTab) ){
-          sqlite3ErrorMsg(pParse, "'%s' is not a function", pTab->zName);
-          return WRC_Abort;
-        }
-        pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
-        sqlite3SelectSetName(pFrom->pSelect, pTab->zName);
-        nCol = pTab->nCol;
-        pTab->nCol = -1;
-        sqlite3WalkSelect(pWalker, pFrom->pSelect);
-        pTab->nCol = nCol;
-      }
-#endif
-    }
-
-    /* Locate the index named by the INDEXED BY clause, if any. */
-    if( sqlite3IndexedByLookup(pParse, pFrom) ){
-      return WRC_Abort;
-    }
-  }
-
-  /* Process NATURAL keywords, and ON and USING clauses of joins.
-  */
-  if( db->mallocFailed || sqliteProcessJoin(pParse, p) ){
-    return WRC_Abort;
-  }
-
-  /* For every "*" that occurs in the column list, insert the names of
-  ** all columns in all tables.  And for every TABLE.* insert the names
-  ** of all columns in TABLE.  The parser inserted a special expression
-  ** with the TK_ALL operator for each "*" that it found in the column list.
-  ** The following code just has to locate the TK_ALL expressions and expand
-  ** each one to the list of all columns in all tables.
-  **
-  ** The first loop just checks to see if there are any "*" operators
-  ** that need expanding.
-  */
-  for(k=0; k<pEList->nExpr; k++){
-    pE = pEList->a[k].pExpr;
-    if( pE->op==TK_ALL ) break;
-    assert( pE->op!=TK_DOT || pE->pRight!=0 );
-    assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
-    if( pE->op==TK_DOT && pE->pRight->op==TK_ALL ) break;
-  }
-  if( k<pEList->nExpr ){
-    /*
-    ** If we get here it means the result set contains one or more "*"
-    ** operators that need to be expanded.  Loop through each expression
-    ** in the result set and expand them one by one.
-    */
-    struct ExprList_item *a = pEList->a;
-    ExprList *pNew = 0;
-    int flags = pParse->db->flags;
-    int longNames = (flags & SQLITE_FullColNames)!=0
-                      && (flags & SQLITE_ShortColNames)==0;
-
-    for(k=0; k<pEList->nExpr; k++){
-      pE = a[k].pExpr;
-      pRight = pE->pRight;
-      assert( pE->op!=TK_DOT || pRight!=0 );
-      if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pRight->op!=TK_ALL) ){
-        /* This particular expression does not need to be expanded.
-        */
-        pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
-        if( pNew ){
-          pNew->a[pNew->nExpr-1].zName = a[k].zName;
-          pNew->a[pNew->nExpr-1].zSpan = a[k].zSpan;
-          a[k].zName = 0;
-          a[k].zSpan = 0;
-        }
-        a[k].pExpr = 0;
-      }else{
-        /* This expression is a "*" or a "TABLE.*" and needs to be
-        ** expanded. */
-        int tableSeen = 0;      /* Set to 1 when TABLE matches */
-        char *zTName = 0;       /* text of name of TABLE */
-        if( pE->op==TK_DOT ){
-          assert( pE->pLeft!=0 );
-          assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );
-          zTName = pE->pLeft->u.zToken;
-        }
-        for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-          Table *pTab = pFrom->pTab;
-          Select *pSub = pFrom->pSelect;
-          char *zTabName = pFrom->zAlias;
-          const char *zSchemaName = 0;
-          int iDb;
-          if( zTabName==0 ){
-            zTabName = pTab->zName;
-          }
-          if( db->mallocFailed ) break;
-          if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
-            pSub = 0;
-            if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
-              continue;
-            }
-            iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
-            zSchemaName = iDb>=0 ? db->aDb[iDb].zName : "*";
-          }
-          for(j=0; j<pTab->nCol; j++){
-            char *zName = pTab->aCol[j].zName;
-            char *zColname;  /* The computed column name */
-            char *zToFree;   /* Malloced string that needs to be freed */
-            Token sColname;  /* Computed column name as a token */
-
-            assert( zName );
-            if( zTName && pSub
-             && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0
-            ){
-              continue;
-            }
-
-            /* If a column is marked as 'hidden' (currently only possible
-            ** for virtual tables), do not include it in the expanded
-            ** result-set list.
-            */
-            if( IsHiddenColumn(&pTab->aCol[j]) ){
-              assert(IsVirtual(pTab));
-              continue;
-            }
-            tableSeen = 1;
-
-            if( i>0 && zTName==0 ){
-              if( (pFrom->fg.jointype & JT_NATURAL)!=0
-                && tableAndColumnIndex(pTabList, i, zName, 0, 0)
-              ){
-                /* In a NATURAL join, omit the join columns from the 
-                ** table to the right of the join */
-                continue;
-              }
-              if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){
-                /* In a join with a USING clause, omit columns in the
-                ** using clause from the table on the right. */
-                continue;
-              }
-            }
-            pRight = sqlite3Expr(db, TK_ID, zName);
-            zColname = zName;
-            zToFree = 0;
-            if( longNames || pTabList->nSrc>1 ){
-              Expr *pLeft;
-              pLeft = sqlite3Expr(db, TK_ID, zTabName);
-              pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
-              if( zSchemaName ){
-                pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
-                pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr, 0);
-              }
-              if( longNames ){
-                zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
-                zToFree = zColname;
-              }
-            }else{
-              pExpr = pRight;
-            }
-            pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
-            sColname.z = zColname;
-            sColname.n = sqlite3Strlen30(zColname);
-            sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
-            if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){
-              struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
-              if( pSub ){
-                pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan);
-                testcase( pX->zSpan==0 );
-              }else{
-                pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s",
-                                           zSchemaName, zTabName, zColname);
-                testcase( pX->zSpan==0 );
-              }
-              pX->bSpanIsTab = 1;
-            }
-            sqlite3DbFree(db, zToFree);
-          }
-        }
-        if( !tableSeen ){
-          if( zTName ){
-            sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
-          }else{
-            sqlite3ErrorMsg(pParse, "no tables specified");
-          }
-        }
-      }
-    }
-    sqlite3ExprListDelete(db, pEList);
-    p->pEList = pNew;
-  }
-#if SQLITE_MAX_COLUMN
-  if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
-    sqlite3ErrorMsg(pParse, "too many columns in result set");
-  }
-#endif
-  return WRC_Continue;
-}
-
-/*
-** No-op routine for the parse-tree walker.
-**
-** When this routine is the Walker.xExprCallback then expression trees
-** are walked without any actions being taken at each node.  Presumably,
-** when this routine is used for Walker.xExprCallback then 
-** Walker.xSelectCallback is set to do something useful for every 
-** subquery in the parser tree.
-*/
-static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
-  UNUSED_PARAMETER2(NotUsed, NotUsed2);
-  return WRC_Continue;
-}
-
-/*
-** This routine "expands" a SELECT statement and all of its subqueries.
-** For additional information on what it means to "expand" a SELECT
-** statement, see the comment on the selectExpand worker callback above.
-**
-** Expanding a SELECT statement is the first step in processing a
-** SELECT statement.  The SELECT statement must be expanded before
-** name resolution is performed.
-**
-** If anything goes wrong, an error message is written into pParse.
-** The calling function can detect the problem by looking at pParse->nErr
-** and/or pParse->db->mallocFailed.
-*/
-static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
-  Walker w;
-  memset(&w, 0, sizeof(w));
-  w.xExprCallback = exprWalkNoop;
-  w.pParse = pParse;
-  if( pParse->hasCompound ){
-    w.xSelectCallback = convertCompoundSelectToSubquery;
-    sqlite3WalkSelect(&w, pSelect);
-  }
-  w.xSelectCallback = selectExpander;
-  if( (pSelect->selFlags & SF_MultiValue)==0 ){
-    w.xSelectCallback2 = selectPopWith;
-  }
-  sqlite3WalkSelect(&w, pSelect);
-}
-
-
-#ifndef SQLITE_OMIT_SUBQUERY
-/*
-** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()
-** interface.
-**
-** For each FROM-clause subquery, add Column.zType and Column.zColl
-** information to the Table structure that represents the result set
-** of that subquery.
-**
-** The Table structure that represents the result set was constructed
-** by selectExpander() but the type and collation information was omitted
-** at that point because identifiers had not yet been resolved.  This
-** routine is called after identifier resolution.
-*/
-static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
-  Parse *pParse;
-  int i;
-  SrcList *pTabList;
-  struct SrcList_item *pFrom;
-
-  assert( p->selFlags & SF_Resolved );
-  assert( (p->selFlags & SF_HasTypeInfo)==0 );
-  p->selFlags |= SF_HasTypeInfo;
-  pParse = pWalker->pParse;
-  pTabList = p->pSrc;
-  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-    Table *pTab = pFrom->pTab;
-    assert( pTab!=0 );
-    if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
-      /* A sub-query in the FROM clause of a SELECT */
-      Select *pSel = pFrom->pSelect;
-      if( pSel ){
-        while( pSel->pPrior ) pSel = pSel->pPrior;
-        selectAddColumnTypeAndCollation(pParse, pTab, pSel);
-      }
-    }
-  }
-}
-#endif
-
-
-/*
-** This routine adds datatype and collating sequence information to
-** the Table structures of all FROM-clause subqueries in a
-** SELECT statement.
-**
-** Use this routine after name resolution.
-*/
-static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
-#ifndef SQLITE_OMIT_SUBQUERY
-  Walker w;
-  memset(&w, 0, sizeof(w));
-  w.xSelectCallback2 = selectAddSubqueryTypeInfo;
-  w.xExprCallback = exprWalkNoop;
-  w.pParse = pParse;
-  sqlite3WalkSelect(&w, pSelect);
-#endif
-}
-
-
-/*
-** This routine sets up a SELECT statement for processing.  The
-** following is accomplished:
-**
-**     *  VDBE Cursor numbers are assigned to all FROM-clause terms.
-**     *  Ephemeral Table objects are created for all FROM-clause subqueries.
-**     *  ON and USING clauses are shifted into WHERE statements
-**     *  Wildcards "*" and "TABLE.*" in result sets are expanded.
-**     *  Identifiers in expression are matched to tables.
-**
-** This routine acts recursively on all subqueries within the SELECT.
-*/
-void sqlite3SelectPrep(
-  Parse *pParse,         /* The parser context */
-  Select *p,             /* The SELECT statement being coded. */
-  NameContext *pOuterNC  /* Name context for container */
-){
-  sqlite3 *db;
-  if( NEVER(p==0) ) return;
-  db = pParse->db;
-  if( db->mallocFailed ) return;
-  if( p->selFlags & SF_HasTypeInfo ) return;
-  sqlite3SelectExpand(pParse, p);
-  if( pParse->nErr || db->mallocFailed ) return;
-  sqlite3ResolveSelectNames(pParse, p, pOuterNC);
-  if( pParse->nErr || db->mallocFailed ) return;
-  sqlite3SelectAddTypeInfo(pParse, p);
-}
-
-/*
-** Reset the aggregate accumulator.
-**
-** The aggregate accumulator is a set of memory cells that hold
-** intermediate results while calculating an aggregate.  This
-** routine generates code that stores NULLs in all of those memory
-** cells.
-*/
-static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  struct AggInfo_func *pFunc;
-  int nReg = pAggInfo->nFunc + pAggInfo->nColumn;
-  if( nReg==0 ) return;
-#ifdef SQLITE_DEBUG
-  /* Verify that all AggInfo registers are within the range specified by
-  ** AggInfo.mnReg..AggInfo.mxReg */
-  assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );
-  for(i=0; i<pAggInfo->nColumn; i++){
-    assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg
-         && pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );
-  }
-  for(i=0; i<pAggInfo->nFunc; i++){
-    assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
-         && pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
-  }
-#endif
-  sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
-  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
-    if( pFunc->iDistinct>=0 ){
-      Expr *pE = pFunc->pExpr;
-      assert( !ExprHasProperty(pE, EP_xIsSelect) );
-      if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){
-        sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one "
-           "argument");
-        pFunc->iDistinct = -1;
-      }else{
-        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList, 0, 0);
-        sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
-                          (char*)pKeyInfo, P4_KEYINFO);
-      }
-    }
-  }
-}
-
-/*
-** Invoke the OP_AggFinalize opcode for every aggregate function
-** in the AggInfo structure.
-*/
-static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  struct AggInfo_func *pF;
-  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
-    ExprList *pList = pF->pExpr->x.pList;
-    assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
-    sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0,
-                      (void*)pF->pFunc, P4_FUNCDEF);
-  }
-}
-
-/*
-** Update the accumulator memory cells for an aggregate based on
-** the current cursor position.
-*/
-static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  int regHit = 0;
-  int addrHitTest = 0;
-  struct AggInfo_func *pF;
-  struct AggInfo_col *pC;
-
-  pAggInfo->directMode = 1;
-  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
-    int nArg;
-    int addrNext = 0;
-    int regAgg;
-    ExprList *pList = pF->pExpr->x.pList;
-    assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
-    if( pList ){
-      nArg = pList->nExpr;
-      regAgg = sqlite3GetTempRange(pParse, nArg);
-      sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);
-    }else{
-      nArg = 0;
-      regAgg = 0;
-    }
-    if( pF->iDistinct>=0 ){
-      addrNext = sqlite3VdbeMakeLabel(v);
-      testcase( nArg==0 );  /* Error condition */
-      testcase( nArg>1 );   /* Also an error */
-      codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
-    }
-    if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
-      CollSeq *pColl = 0;
-      struct ExprList_item *pItem;
-      int j;
-      assert( pList!=0 );  /* pList!=0 if pF->pFunc has NEEDCOLL */
-      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
-        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      }
-      if( !pColl ){
-        pColl = pParse->db->pDfltColl;
-      }
-      if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;
-      sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);
-    }
-    sqlite3VdbeAddOp4(v, OP_AggStep0, 0, regAgg, pF->iMem,
-                      (void*)pF->pFunc, P4_FUNCDEF);
-    sqlite3VdbeChangeP5(v, (u8)nArg);
-    sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
-    sqlite3ReleaseTempRange(pParse, regAgg, nArg);
-    if( addrNext ){
-      sqlite3VdbeResolveLabel(v, addrNext);
-      sqlite3ExprCacheClear(pParse);
-    }
-  }
-
-  /* Before populating the accumulator registers, clear the column cache.
-  ** Otherwise, if any of the required column values are already present 
-  ** in registers, sqlite3ExprCode() may use OP_SCopy to copy the value
-  ** to pC->iMem. But by the time the value is used, the original register
-  ** may have been used, invalidating the underlying buffer holding the
-  ** text or blob value. See ticket [883034dcb5].
-  **
-  ** Another solution would be to change the OP_SCopy used to copy cached
-  ** values to an OP_Copy.
-  */
-  if( regHit ){
-    addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
-  }
-  sqlite3ExprCacheClear(pParse);
-  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
-    sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
-  }
-  pAggInfo->directMode = 0;
-  sqlite3ExprCacheClear(pParse);
-  if( addrHitTest ){
-    sqlite3VdbeJumpHere(v, addrHitTest);
-  }
-}
-
-/*
-** Add a single OP_Explain instruction to the VDBE to explain a simple
-** count(*) query ("SELECT count(*) FROM pTab").
-*/
-#ifndef SQLITE_OMIT_EXPLAIN
-static void explainSimpleCount(
-  Parse *pParse,                  /* Parse context */
-  Table *pTab,                    /* Table being queried */
-  Index *pIdx                     /* Index used to optimize scan, or NULL */
-){
-  if( pParse->explain==2 ){
-    int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));
-    char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s%s%s",
-        pTab->zName,
-        bCover ? " USING COVERING INDEX " : "",
-        bCover ? pIdx->zName : ""
-    );
-    sqlite3VdbeAddOp4(
-        pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC
-    );
-  }
-}
-#else
-# define explainSimpleCount(a,b,c)
-#endif
-
-/*
-** Generate code for the SELECT statement given in the p argument.  
-**
-** The results are returned according to the SelectDest structure.
-** See comments in sqliteInt.h for further information.
-**
-** This routine returns the number of errors.  If any errors are
-** encountered, then an appropriate error message is left in
-** pParse->zErrMsg.
-**
-** This routine does NOT free the Select structure passed in.  The
-** calling function needs to do that.
-*/
-int sqlite3Select(
-  Parse *pParse,         /* The parser context */
-  Select *p,             /* The SELECT statement being coded. */
-  SelectDest *pDest      /* What to do with the query results */
-){
-  int i, j;              /* Loop counters */
-  WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */
-  Vdbe *v;               /* The virtual machine under construction */
-  int isAgg;             /* True for select lists like "count(*)" */
-  ExprList *pEList = 0;  /* List of columns to extract. */
-  SrcList *pTabList;     /* List of tables to select from */
-  Expr *pWhere;          /* The WHERE clause.  May be NULL */
-  ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */
-  Expr *pHaving;         /* The HAVING clause.  May be NULL */
-  int rc = 1;            /* Value to return from this function */
-  DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
-  SortCtx sSort;         /* Info on how to code the ORDER BY clause */
-  AggInfo sAggInfo;      /* Information used by aggregate queries */
-  int iEnd;              /* Address of the end of the query */
-  sqlite3 *db;           /* The database connection */
-
-#ifndef SQLITE_OMIT_EXPLAIN
-  int iRestoreSelectId = pParse->iSelectId;
-  pParse->iSelectId = pParse->iNextSelectId++;
-#endif
-
-  db = pParse->db;
-  if( p==0 || db->mallocFailed || pParse->nErr ){
-    return 1;
-  }
-  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
-  memset(&sAggInfo, 0, sizeof(sAggInfo));
-#if SELECTTRACE_ENABLED
-  pParse->nSelectIndent++;
-  SELECTTRACE(1,pParse,p, ("begin processing:\n"));
-  if( sqlite3SelectTrace & 0x100 ){
-    sqlite3TreeViewSelect(0, p, 0);
-  }
-#endif
-
-  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );
-  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
-  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
-  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
-  if( IgnorableOrderby(pDest) ){
-    assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
-           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
-           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
-           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
-    /* If ORDER BY makes no difference in the output then neither does
-    ** DISTINCT so it can be removed too. */
-    sqlite3ExprListDelete(db, p->pOrderBy);
-    p->pOrderBy = 0;
-    p->selFlags &= ~SF_Distinct;
-  }
-  sqlite3SelectPrep(pParse, p, 0);
-  memset(&sSort, 0, sizeof(sSort));
-  sSort.pOrderBy = p->pOrderBy;
-  pTabList = p->pSrc;
-  if( pParse->nErr || db->mallocFailed ){
-    goto select_end;
-  }
-  assert( p->pEList!=0 );
-  isAgg = (p->selFlags & SF_Aggregate)!=0;
-#if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x100 ){
-    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
-    sqlite3TreeViewSelect(0, p, 0);
-  }
-#endif
-
-
-  /* If writing to memory or generating a set
-  ** only a single column may be output.
-  */
-#ifndef SQLITE_OMIT_SUBQUERY
-  if( checkForMultiColumnSelectError(pParse, pDest, p->pEList->nExpr) ){
-    goto select_end;
-  }
-#endif
-
-  /* Try to flatten subqueries in the FROM clause up into the main query
-  */
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
-    struct SrcList_item *pItem = &pTabList->a[i];
-    Select *pSub = pItem->pSelect;
-    int isAggSub;
-    Table *pTab = pItem->pTab;
-    if( pSub==0 ) continue;
-
-    /* Catch mismatch in the declared columns of a view and the number of
-    ** columns in the SELECT on the RHS */
-    if( pTab->nCol!=pSub->pEList->nExpr ){
-      sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
-                      pTab->nCol, pTab->zName, pSub->pEList->nExpr);
-      goto select_end;
-    }
-
-    isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
-    if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
-      /* This subquery can be absorbed into its parent. */
-      if( isAggSub ){
-        isAgg = 1;
-        p->selFlags |= SF_Aggregate;
-      }
-      i = -1;
-    }
-    pTabList = p->pSrc;
-    if( db->mallocFailed ) goto select_end;
-    if( !IgnorableOrderby(pDest) ){
-      sSort.pOrderBy = p->pOrderBy;
-    }
-  }
-#endif
-
-  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
-  ** does not already exist */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ) goto select_end;
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-  /* Handle compound SELECT statements using the separate multiSelect()
-  ** procedure.
-  */
-  if( p->pPrior ){
-    rc = multiSelect(pParse, p, pDest);
-    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
-#if SELECTTRACE_ENABLED
-    SELECTTRACE(1,pParse,p,("end compound-select processing\n"));
-    pParse->nSelectIndent--;
-#endif
-    return rc;
-  }
-#endif
-
-  /* Generate code for all sub-queries in the FROM clause
-  */
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-  for(i=0; i<pTabList->nSrc; i++){
-    struct SrcList_item *pItem = &pTabList->a[i];
-    SelectDest dest;
-    Select *pSub = pItem->pSelect;
-    if( pSub==0 ) continue;
-
-    /* Sometimes the code for a subquery will be generated more than
-    ** once, if the subquery is part of the WHERE clause in a LEFT JOIN,
-    ** for example.  In that case, do not regenerate the code to manifest
-    ** a view or the co-routine to implement a view.  The first instance
-    ** is sufficient, though the subroutine to manifest the view does need
-    ** to be invoked again. */
-    if( pItem->addrFillSub ){
-      if( pItem->fg.viaCoroutine==0 ){
-        sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
-      }
-      continue;
-    }
-
-    /* Increment Parse.nHeight by the height of the largest expression
-    ** tree referred to by this, the parent select. The child select
-    ** may contain expression trees of at most
-    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
-    ** more conservative than necessary, but much easier than enforcing
-    ** an exact limit.
-    */
-    pParse->nHeight += sqlite3SelectExprHeight(p);
-
-    /* Make copies of constant WHERE-clause terms in the outer query down
-    ** inside the subquery.  This can help the subquery to run more efficiently.
-    */
-    if( (pItem->fg.jointype & JT_OUTER)==0
-     && pushDownWhereTerms(db, pSub, p->pWhere, pItem->iCursor)
-    ){
-#if SELECTTRACE_ENABLED
-      if( sqlite3SelectTrace & 0x100 ){
-        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
-        sqlite3TreeViewSelect(0, p, 0);
-      }
-#endif
-    }
-
-    /* Generate code to implement the subquery
-    */
-    if( pTabList->nSrc==1
-     && (p->selFlags & SF_All)==0
-     && OptimizationEnabled(db, SQLITE_SubqCoroutine)
-    ){
-      /* Implement a co-routine that will return a single row of the result
-      ** set on each invocation.
-      */
-      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
-      pItem->regReturn = ++pParse->nMem;
-      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
-      VdbeComment((v, "%s", pItem->pTab->zName));
-      pItem->addrFillSub = addrTop;
-      sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
-      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
-      sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
-      pItem->fg.viaCoroutine = 1;
-      pItem->regResult = dest.iSdst;
-      sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn);
-      sqlite3VdbeJumpHere(v, addrTop-1);
-      sqlite3ClearTempRegCache(pParse);
-    }else{
-      /* Generate a subroutine that will fill an ephemeral table with
-      ** the content of this subquery.  pItem->addrFillSub will point
-      ** to the address of the generated subroutine.  pItem->regReturn
-      ** is a register allocated to hold the subroutine return address
-      */
-      int topAddr;
-      int onceAddr = 0;
-      int retAddr;
-      assert( pItem->addrFillSub==0 );
-      pItem->regReturn = ++pParse->nMem;
-      topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
-      pItem->addrFillSub = topAddr+1;
-      if( pItem->fg.isCorrelated==0 ){
-        /* If the subquery is not correlated and if we are not inside of
-        ** a trigger, then we only need to compute the value of the subquery
-        ** once. */
-        onceAddr = sqlite3CodeOnce(pParse); VdbeCoverage(v);
-        VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
-      }else{
-        VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
-      }
-      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
-      sqlite3Select(pParse, pSub, &dest);
-      pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow);
-      if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
-      retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
-      VdbeComment((v, "end %s", pItem->pTab->zName));
-      sqlite3VdbeChangeP1(v, topAddr, retAddr);
-      sqlite3ClearTempRegCache(pParse);
-    }
-    if( db->mallocFailed ) goto select_end;
-    pParse->nHeight -= sqlite3SelectExprHeight(p);
-  }
-#endif
-
-  /* Various elements of the SELECT copied into local variables for
-  ** convenience */
-  pEList = p->pEList;
-  pWhere = p->pWhere;
-  pGroupBy = p->pGroupBy;
-  pHaving = p->pHaving;
-  sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;
-
-#if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x400 ){
-    SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
-    sqlite3TreeViewSelect(0, p, 0);
-  }
-#endif
-
-  /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and 
-  ** if the select-list is the same as the ORDER BY list, then this query
-  ** can be rewritten as a GROUP BY. In other words, this:
-  **
-  **     SELECT DISTINCT xyz FROM ... ORDER BY xyz
-  **
-  ** is transformed to:
-  **
-  **     SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz
-  **
-  ** The second form is preferred as a single index (or temp-table) may be 
-  ** used for both the ORDER BY and DISTINCT processing. As originally 
-  ** written the query must use a temp-table for at least one of the ORDER 
-  ** BY and DISTINCT, and an index or separate temp-table for the other.
-  */
-  if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
-   && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
-  ){
-    p->selFlags &= ~SF_Distinct;
-    pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
-    /* Notice that even thought SF_Distinct has been cleared from p->selFlags,
-    ** the sDistinct.isTnct is still set.  Hence, isTnct represents the
-    ** original setting of the SF_Distinct flag, not the current setting */
-    assert( sDistinct.isTnct );
-  }
-
-  /* If there is an ORDER BY clause, then create an ephemeral index to
-  ** do the sorting.  But this sorting ephemeral index might end up
-  ** being unused if the data can be extracted in pre-sorted order.
-  ** If that is the case, then the OP_OpenEphemeral instruction will be
-  ** changed to an OP_Noop once we figure out that the sorting index is
-  ** not needed.  The sSort.addrSortIndex variable is used to facilitate
-  ** that change.
-  */
-  if( sSort.pOrderBy ){
-    KeyInfo *pKeyInfo;
-    pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, pEList->nExpr);
-    sSort.iECursor = pParse->nTab++;
-    sSort.addrSortIndex =
-      sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
-          sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
-          (char*)pKeyInfo, P4_KEYINFO
-      );
-  }else{
-    sSort.addrSortIndex = -1;
-  }
-
-  /* If the output is destined for a temporary table, open that table.
-  */
-  if( pDest->eDest==SRT_EphemTab ){
-    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);
-  }
-
-  /* Set the limiter.
-  */
-  iEnd = sqlite3VdbeMakeLabel(v);
-  p->nSelectRow = LARGEST_INT64;
-  computeLimitRegisters(pParse, p, iEnd);
-  if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
-    sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
-    sSort.sortFlags |= SORTFLAG_UseSorter;
-  }
-
-  /* Open an ephemeral index to use for the distinct set.
-  */
-  if( p->selFlags & SF_Distinct ){
-    sDistinct.tabTnct = pParse->nTab++;
-    sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
-                             sDistinct.tabTnct, 0, 0,
-                             (char*)keyInfoFromExprList(pParse, p->pEList,0,0),
-                             P4_KEYINFO);
-    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
-    sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
-  }else{
-    sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
-  }
-
-  if( !isAgg && pGroupBy==0 ){
-    /* No aggregate functions and no GROUP BY clause */
-    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0);
-
-    /* Begin the database scan. */
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
-                               p->pEList, wctrlFlags, 0);
-    if( pWInfo==0 ) goto select_end;
-    if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
-      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
-    }
-    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
-      sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
-    }
-    if( sSort.pOrderBy ){
-      sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
-      if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
-        sSort.pOrderBy = 0;
-      }
-    }
-
-    /* If sorting index that was created by a prior OP_OpenEphemeral 
-    ** instruction ended up not being needed, then change the OP_OpenEphemeral
-    ** into an OP_Noop.
-    */
-    if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){
-      sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
-    }
-
-    /* Use the standard inner loop. */
-    selectInnerLoop(pParse, p, pEList, -1, &sSort, &sDistinct, pDest,
-                    sqlite3WhereContinueLabel(pWInfo),
-                    sqlite3WhereBreakLabel(pWInfo));
-
-    /* End the database scan loop.
-    */
-    sqlite3WhereEnd(pWInfo);
-  }else{
-    /* This case when there exist aggregate functions or a GROUP BY clause
-    ** or both */
-    NameContext sNC;    /* Name context for processing aggregate information */
-    int iAMem;          /* First Mem address for storing current GROUP BY */
-    int iBMem;          /* First Mem address for previous GROUP BY */
-    int iUseFlag;       /* Mem address holding flag indicating that at least
-                        ** one row of the input to the aggregator has been
-                        ** processed */
-    int iAbortFlag;     /* Mem address which causes query abort if positive */
-    int groupBySort;    /* Rows come from source in GROUP BY order */
-    int addrEnd;        /* End of processing for this SELECT */
-    int sortPTab = 0;   /* Pseudotable used to decode sorting results */
-    int sortOut = 0;    /* Output register from the sorter */
-    int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */
-
-    /* Remove any and all aliases between the result set and the
-    ** GROUP BY clause.
-    */
-    if( pGroupBy ){
-      int k;                        /* Loop counter */
-      struct ExprList_item *pItem;  /* For looping over expression in a list */
-
-      for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){
-        pItem->u.x.iAlias = 0;
-      }
-      for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
-        pItem->u.x.iAlias = 0;
-      }
-      if( p->nSelectRow>100 ) p->nSelectRow = 100;
-    }else{
-      p->nSelectRow = 1;
-    }
-
-    /* If there is both a GROUP BY and an ORDER BY clause and they are
-    ** identical, then it may be possible to disable the ORDER BY clause 
-    ** on the grounds that the GROUP BY will cause elements to come out 
-    ** in the correct order. It also may not - the GROUP BY might use a
-    ** database index that causes rows to be grouped together as required
-    ** but not actually sorted. Either way, record the fact that the
-    ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp
-    ** variable.  */
-    if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){
-      orderByGrp = 1;
-    }
- 
-    /* Create a label to jump to when we want to abort the query */
-    addrEnd = sqlite3VdbeMakeLabel(v);
-
-    /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
-    ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
-    ** SELECT statement.
-    */
-    memset(&sNC, 0, sizeof(sNC));
-    sNC.pParse = pParse;
-    sNC.pSrcList = pTabList;
-    sNC.pAggInfo = &sAggInfo;
-    sAggInfo.mnReg = pParse->nMem+1;
-    sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;
-    sAggInfo.pGroupBy = pGroupBy;
-    sqlite3ExprAnalyzeAggList(&sNC, pEList);
-    sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);
-    if( pHaving ){
-      sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
-    }
-    sAggInfo.nAccumulator = sAggInfo.nColumn;
-    for(i=0; i<sAggInfo.nFunc; i++){
-      assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );
-      sNC.ncFlags |= NC_InAggFunc;
-      sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
-      sNC.ncFlags &= ~NC_InAggFunc;
-    }
-    sAggInfo.mxReg = pParse->nMem;
-    if( db->mallocFailed ) goto select_end;
-
-    /* Processing for aggregates with GROUP BY is very different and
-    ** much more complex than aggregates without a GROUP BY.
-    */
-    if( pGroupBy ){
-      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
-      int addr1;          /* A-vs-B comparision jump */
-      int addrOutputRow;  /* Start of subroutine that outputs a result row */
-      int regOutputRow;   /* Return address register for output subroutine */
-      int addrSetAbort;   /* Set the abort flag and return */
-      int addrTopOfLoop;  /* Top of the input loop */
-      int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
-      int addrReset;      /* Subroutine for resetting the accumulator */
-      int regReset;       /* Return address register for reset subroutine */
-
-      /* If there is a GROUP BY clause we might need a sorting index to
-      ** implement it.  Allocate that sorting index now.  If it turns out
-      ** that we do not need it after all, the OP_SorterOpen instruction
-      ** will be converted into a Noop.  
-      */
-      sAggInfo.sortingIdx = pParse->nTab++;
-      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0, sAggInfo.nColumn);
-      addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, 
-          sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 
-          0, (char*)pKeyInfo, P4_KEYINFO);
-
-      /* Initialize memory locations used by GROUP BY aggregate processing
-      */
-      iUseFlag = ++pParse->nMem;
-      iAbortFlag = ++pParse->nMem;
-      regOutputRow = ++pParse->nMem;
-      addrOutputRow = sqlite3VdbeMakeLabel(v);
-      regReset = ++pParse->nMem;
-      addrReset = sqlite3VdbeMakeLabel(v);
-      iAMem = pParse->nMem + 1;
-      pParse->nMem += pGroupBy->nExpr;
-      iBMem = pParse->nMem + 1;
-      pParse->nMem += pGroupBy->nExpr;
-      sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag);
-      VdbeComment((v, "clear abort flag"));
-      sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
-      VdbeComment((v, "indicate accumulator empty"));
-      sqlite3VdbeAddOp3(v, OP_Null, 0, iAMem, iAMem+pGroupBy->nExpr-1);
-
-      /* Begin a loop that will extract all source rows in GROUP BY order.
-      ** This might involve two separate loops with an OP_Sort in between, or
-      ** it might be a single loop that uses an index to extract information
-      ** in the right order to begin with.
-      */
-      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
-      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
-          WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0
-      );
-      if( pWInfo==0 ) goto select_end;
-      if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){
-        /* The optimizer is able to deliver rows in group by order so
-        ** we do not have to sort.  The OP_OpenEphemeral table will be
-        ** cancelled later because we still need to use the pKeyInfo
-        */
-        groupBySort = 0;
-      }else{
-        /* Rows are coming out in undetermined order.  We have to push
-        ** each row into a sorting index, terminate the first loop,
-        ** then loop over the sorting index in order to get the output
-        ** in sorted order
-        */
-        int regBase;
-        int regRecord;
-        int nCol;
-        int nGroupBy;
-
-        explainTempTable(pParse, 
-            (sDistinct.isTnct && (p->selFlags&SF_Distinct)==0) ?
-                    "DISTINCT" : "GROUP BY");
-
-        groupBySort = 1;
-        nGroupBy = pGroupBy->nExpr;
-        nCol = nGroupBy;
-        j = nGroupBy;
-        for(i=0; i<sAggInfo.nColumn; i++){
-          if( sAggInfo.aCol[i].iSorterColumn>=j ){
-            nCol++;
-            j++;
-          }
-        }
-        regBase = sqlite3GetTempRange(pParse, nCol);
-        sqlite3ExprCacheClear(pParse);
-        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);
-        j = nGroupBy;
-        for(i=0; i<sAggInfo.nColumn; i++){
-          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
-          if( pCol->iSorterColumn>=j ){
-            int r1 = j + regBase;
-            int r2;
-
-            r2 = sqlite3ExprCodeGetColumn(pParse, 
-                               pCol->pTab, pCol->iColumn, pCol->iTable, r1, 0);
-            if( r1!=r2 ){
-              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
-            }
-            j++;
-          }
-        }
-        regRecord = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
-        sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);
-        sqlite3ReleaseTempReg(pParse, regRecord);
-        sqlite3ReleaseTempRange(pParse, regBase, nCol);
-        sqlite3WhereEnd(pWInfo);
-        sAggInfo.sortingIdxPTab = sortPTab = pParse->nTab++;
-        sortOut = sqlite3GetTempReg(pParse);
-        sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
-        sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
-        VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v);
-        sAggInfo.useSortingIdx = 1;
-        sqlite3ExprCacheClear(pParse);
-
-      }
-
-      /* If the index or temporary table used by the GROUP BY sort
-      ** will naturally deliver rows in the order required by the ORDER BY
-      ** clause, cancel the ephemeral table open coded earlier.
-      **
-      ** This is an optimization - the correct answer should result regardless.
-      ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to 
-      ** disable this optimization for testing purposes.  */
-      if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder) 
-       && (groupBySort || sqlite3WhereIsSorted(pWInfo))
-      ){
-        sSort.pOrderBy = 0;
-        sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
-      }
-
-      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
-      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
-      ** Then compare the current GROUP BY terms against the GROUP BY terms
-      ** from the previous row currently stored in a0, a1, a2...
-      */
-      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
-      sqlite3ExprCacheClear(pParse);
-      if( groupBySort ){
-        sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx,
-                          sortOut, sortPTab);
-      }
-      for(j=0; j<pGroupBy->nExpr; j++){
-        if( groupBySort ){
-          sqlite3VdbeAddOp3(v, OP_Column, sortPTab, j, iBMem+j);
-        }else{
-          sAggInfo.directMode = 1;
-          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
-        }
-      }
-      sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
-                          (char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
-      addr1 = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);
-
-      /* Generate code that runs whenever the GROUP BY changes.
-      ** Changes in the GROUP BY are detected by the previous code
-      ** block.  If there were no changes, this block is skipped.
-      **
-      ** This code copies current group by terms in b0,b1,b2,...
-      ** over to a0,a1,a2.  It then calls the output subroutine
-      ** and resets the aggregate accumulator registers in preparation
-      ** for the next GROUP BY batch.
-      */
-      sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
-      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
-      VdbeComment((v, "output one row"));
-      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);
-      VdbeComment((v, "check abort flag"));
-      sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
-      VdbeComment((v, "reset accumulator"));
-
-      /* Update the aggregate accumulators based on the content of
-      ** the current row
-      */
-      sqlite3VdbeJumpHere(v, addr1);
-      updateAccumulator(pParse, &sAggInfo);
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
-      VdbeComment((v, "indicate data in accumulator"));
-
-      /* End of the loop
-      */
-      if( groupBySort ){
-        sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);
-        VdbeCoverage(v);
-      }else{
-        sqlite3WhereEnd(pWInfo);
-        sqlite3VdbeChangeToNoop(v, addrSortingIdx);
-      }
-
-      /* Output the final row of result
-      */
-      sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
-      VdbeComment((v, "output final row"));
-
-      /* Jump over the subroutines
-      */
-      sqlite3VdbeGoto(v, addrEnd);
-
-      /* Generate a subroutine that outputs a single row of the result
-      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
-      ** is less than or equal to zero, the subroutine is a no-op.  If
-      ** the processing calls for the query to abort, this subroutine
-      ** increments the iAbortFlag memory location before returning in
-      ** order to signal the caller to abort.
-      */
-      addrSetAbort = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
-      VdbeComment((v, "set abort flag"));
-      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
-      sqlite3VdbeResolveLabel(v, addrOutputRow);
-      addrOutputRow = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
-      VdbeCoverage(v);
-      VdbeComment((v, "Groupby result generator entry point"));
-      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
-      finalizeAggFunctions(pParse, &sAggInfo);
-      sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
-      selectInnerLoop(pParse, p, p->pEList, -1, &sSort,
-                      &sDistinct, pDest,
-                      addrOutputRow+1, addrSetAbort);
-      sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
-      VdbeComment((v, "end groupby result generator"));
-
-      /* Generate a subroutine that will reset the group-by accumulator
-      */
-      sqlite3VdbeResolveLabel(v, addrReset);
-      resetAccumulator(pParse, &sAggInfo);
-      sqlite3VdbeAddOp1(v, OP_Return, regReset);
-     
-    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */
-    else {
-      ExprList *pDel = 0;
-#ifndef SQLITE_OMIT_BTREECOUNT
-      Table *pTab;
-      if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){
-        /* If isSimpleCount() returns a pointer to a Table structure, then
-        ** the SQL statement is of the form:
-        **
-        **   SELECT count(*) FROM <tbl>
-        **
-        ** where the Table structure returned represents table <tbl>.
-        **
-        ** This statement is so common that it is optimized specially. The
-        ** OP_Count instruction is executed either on the intkey table that
-        ** contains the data for table <tbl> or on one of its indexes. It
-        ** is better to execute the op on an index, as indexes are almost
-        ** always spread across less pages than their corresponding tables.
-        */
-        const int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
-        const int iCsr = pParse->nTab++;     /* Cursor to scan b-tree */
-        Index *pIdx;                         /* Iterator variable */
-        KeyInfo *pKeyInfo = 0;               /* Keyinfo for scanned index */
-        Index *pBest = 0;                    /* Best index found so far */
-        int iRoot = pTab->tnum;              /* Root page of scanned b-tree */
-
-        sqlite3CodeVerifySchema(pParse, iDb);
-        sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
-
-        /* Search for the index that has the lowest scan cost.
-        **
-        ** (2011-04-15) Do not do a full scan of an unordered index.
-        **
-        ** (2013-10-03) Do not count the entries in a partial index.
-        **
-        ** In practice the KeyInfo structure will not be used. It is only 
-        ** passed to keep OP_OpenRead happy.
-        */
-        if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);
-        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-          if( pIdx->bUnordered==0
-           && pIdx->szIdxRow<pTab->szTabRow
-           && pIdx->pPartIdxWhere==0
-           && (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
-          ){
-            pBest = pIdx;
-          }
-        }
-        if( pBest ){
-          iRoot = pBest->tnum;
-          pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);
-        }
-
-        /* Open a read-only cursor, execute the OP_Count, close the cursor. */
-        sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, iRoot, iDb, 1);
-        if( pKeyInfo ){
-          sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
-        }
-        sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
-        sqlite3VdbeAddOp1(v, OP_Close, iCsr);
-        explainSimpleCount(pParse, pTab, pBest);
-      }else
-#endif /* SQLITE_OMIT_BTREECOUNT */
-      {
-        /* Check if the query is of one of the following forms:
-        **
-        **   SELECT min(x) FROM ...
-        **   SELECT max(x) FROM ...
-        **
-        ** If it is, then ask the code in where.c to attempt to sort results
-        ** as if there was an "ORDER ON x" or "ORDER ON x DESC" clause. 
-        ** If where.c is able to produce results sorted in this order, then
-        ** add vdbe code to break out of the processing loop after the 
-        ** first iteration (since the first iteration of the loop is 
-        ** guaranteed to operate on the row with the minimum or maximum 
-        ** value of x, the only row required).
-        **
-        ** A special flag must be passed to sqlite3WhereBegin() to slightly
-        ** modify behavior as follows:
-        **
-        **   + If the query is a "SELECT min(x)", then the loop coded by
-        **     where.c should not iterate over any values with a NULL value
-        **     for x.
-        **
-        **   + The optimizer code in where.c (the thing that decides which
-        **     index or indices to use) should place a different priority on 
-        **     satisfying the 'ORDER BY' clause than it does in other cases.
-        **     Refer to code and comments in where.c for details.
-        */
-        ExprList *pMinMax = 0;
-        u8 flag = WHERE_ORDERBY_NORMAL;
-        
-        assert( p->pGroupBy==0 );
-        assert( flag==0 );
-        if( p->pHaving==0 ){
-          flag = minMaxQuery(&sAggInfo, &pMinMax);
-        }
-        assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) );
-
-        if( flag ){
-          pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
-          pDel = pMinMax;
-          if( pMinMax && !db->mallocFailed ){
-            pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
-            pMinMax->a[0].pExpr->op = TK_COLUMN;
-          }
-        }
-  
-        /* This case runs if the aggregate has no GROUP BY clause.  The
-        ** processing is much simpler since there is only a single row
-        ** of output.
-        */
-        resetAccumulator(pParse, &sAggInfo);
-        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMax,0,flag,0);
-        if( pWInfo==0 ){
-          sqlite3ExprListDelete(db, pDel);
-          goto select_end;
-        }
-        updateAccumulator(pParse, &sAggInfo);
-        assert( pMinMax==0 || pMinMax->nExpr==1 );
-        if( sqlite3WhereIsOrdered(pWInfo)>0 ){
-          sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
-          VdbeComment((v, "%s() by index",
-                (flag==WHERE_ORDERBY_MIN?"min":"max")));
-        }
-        sqlite3WhereEnd(pWInfo);
-        finalizeAggFunctions(pParse, &sAggInfo);
-      }
-
-      sSort.pOrderBy = 0;
-      sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
-      selectInnerLoop(pParse, p, p->pEList, -1, 0, 0, 
-                      pDest, addrEnd, addrEnd);
-      sqlite3ExprListDelete(db, pDel);
-    }
-    sqlite3VdbeResolveLabel(v, addrEnd);
-    
-  } /* endif aggregate query */
-
-  if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
-    explainTempTable(pParse, "DISTINCT");
-  }
-
-  /* If there is an ORDER BY clause, then we need to sort the results
-  ** and send them to the callback one by one.
-  */
-  if( sSort.pOrderBy ){
-    explainTempTable(pParse,
-                     sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
-    generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
-  }
-
-  /* Jump here to skip this query
-  */
-  sqlite3VdbeResolveLabel(v, iEnd);
-
-  /* The SELECT has been coded. If there is an error in the Parse structure,
-  ** set the return code to 1. Otherwise 0. */
-  rc = (pParse->nErr>0);
-
-  /* Control jumps to here if an error is encountered above, or upon
-  ** successful coding of the SELECT.
-  */
-select_end:
-  explainSetInteger(pParse->iSelectId, iRestoreSelectId);
-
-  /* Identify column names if results of the SELECT are to be output.
-  */
-  if( rc==SQLITE_OK && pDest->eDest==SRT_Output ){
-    generateColumnNames(pParse, pTabList, pEList);
-  }
-
-  sqlite3DbFree(db, sAggInfo.aCol);
-  sqlite3DbFree(db, sAggInfo.aFunc);
-#if SELECTTRACE_ENABLED
-  SELECTTRACE(1,pParse,p,("end processing\n"));
-  pParse->nSelectIndent--;
-#endif
-  return rc;
-}